fix(navigation): back button on host detail returns to application when coming from there

- application_detail: host links now include ?back=/applications/:id
- host_detail: back_label handles /applications/ prefix → "← Application"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Cargo.toml

@@ -6,6 +6,15 @@ edition = "2021"
 # Leptos nécessite deux formats de compilation :
 # - rlib   : bibliothèque normale, utilisée par le serveur Axum
 # - cdylib : bibliothèque dynamique compilée en WebAssembly pour le navigateur
+[[bin]]
+name = "rust-ipam"
+path = "src/main.rs"
+
+[[bin]]
+name = "seed"
+path = "src/bin/seed.rs"
+required-features = ["ssr"]
+
 [lib]
 crate-type = ["cdylib", "rlib"]
 
@@ -93,6 +102,7 @@ site-addr = "127.0.0.1:3000"  # Adresse d'écoute du serveur Axum
 reload-port = 3001             # Port WebSocket pour le hot-reload en développement
 style-file = "style/rust-ipam.css"  # Source CSS compilé dans pkg/rust-ipam.css
 # Features activées par cargo-leptos lors du build
+bin-target = "rust-ipam"      # Main server binary (excludes src/bin/seed.rs)
 bin-features = ["ssr"]        # SSR binary (Axum server)
 lib-features = ["hydrate"]    # WASM bundle (browser)
 

migrations/postgres/0008_create_host_applications.sql

@@ -0,0 +1,8 @@
+-- host_applications: direct association between a host and an application.
+-- Allows explicitly tagging a host with an application regardless of ports.
+-- One application can only be linked once to a given host.
+CREATE TABLE IF NOT EXISTS host_applications (
+    host_id        BIGINT NOT NULL REFERENCES hosts(id)        ON DELETE CASCADE,
+    application_id BIGINT NOT NULL REFERENCES applications(id) ON DELETE CASCADE,
+    PRIMARY KEY (host_id, application_id)
+);

migrations/sqlite/0008_create_host_applications.sql

@@ -0,0 +1,8 @@
+-- host_applications: direct association between a host and an application.
+-- Allows explicitly tagging a host with an application regardless of ports.
+-- One application can only be linked once to a given host.
+CREATE TABLE IF NOT EXISTS host_applications (
+    host_id        INTEGER NOT NULL REFERENCES hosts(id)        ON DELETE CASCADE,
+    application_id INTEGER NOT NULL REFERENCES applications(id) ON DELETE CASCADE,
+    PRIMARY KEY (host_id, application_id)
+);

seeds/postgres/dev_seed.sql

@@ -60,3 +60,227 @@ FROM (VALUES
     ('vpn-client-02',  '172.16.1.11')
 ) AS t(name, ip)
 WHERE NOT EXISTS (SELECT 1 FROM hosts WHERE hosts.name = t.name AND hosts.ip = t.ip);
+
+-- ── Ports catalog ─────────────────────────────────────────────────────────────
+
+INSERT INTO ports (number, description) VALUES
+    (22,    'SSH'),
+    (25,    'SMTP'),
+    (53,    'DNS'),
+    (80,    'HTTP'),
+    (143,   'IMAP'),
+    (161,   'SNMP'),
+    (443,   'HTTPS'),
+    (445,   'SMB'),
+    (465,   'SMTPS'),
+    (500,   'IKE / IPSec'),
+    (514,   'Syslog'),
+    (587,   'SMTP Submission'),
+    (873,   'rsync'),
+    (993,   'IMAPS'),
+    (1194,  'OpenVPN'),
+    (2049,  'NFS'),
+    (3000,  'Grafana / Gitea'),
+    (3306,  'MariaDB / MySQL'),
+    (3389,  'RDP'),
+    (4500,  'IPSec NAT-T'),
+    (5044,  'Logstash Beats'),
+    (5432,  'PostgreSQL'),
+    (5601,  'Kibana'),
+    (6379,  'Redis'),
+    (8096,  'Jellyfin'),
+    (8123,  'Home Assistant'),
+    (8384,  'Syncthing UI'),
+    (8920,  'Jellyfin HTTPS'),
+    (9000,  'Portainer'),
+    (9090,  'Prometheus'),
+    (9100,  'node_exporter / JetDirect'),
+    (9200,  'Elasticsearch'),
+    (9443,  'Portainer HTTPS'),
+    (22000, 'Syncthing'),
+    (51820, 'WireGuard')
+ON CONFLICT (number) DO NOTHING;
+
+-- ── Host ports ────────────────────────────────────────────────────────────────
+
+-- gateway: SSH, DNS, HTTP, HTTPS
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 53, 80, 443]) p
+WHERE h.name = 'gateway' AND h.ip = '192.168.1.1'
+ON CONFLICT DO NOTHING;
+
+-- workstation-01: SSH, RDP
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 3389]) p
+WHERE h.name = 'workstation-01' AND h.ip = '192.168.1.10'
+ON CONFLICT DO NOTHING;
+
+-- workstation-02: SSH, RDP
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 3389]) p
+WHERE h.name = 'workstation-02' AND h.ip = '192.168.1.11'
+ON CONFLICT DO NOTHING;
+
+-- workstation-03: SSH, RDP
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 3389]) p
+WHERE h.name = 'workstation-03' AND h.ip = '192.168.1.12'
+ON CONFLICT DO NOTHING;
+
+-- nas-01: SSH, HTTP, HTTPS, SMB, NFS
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 80, 443, 445, 2049]) p
+WHERE h.name = 'nas-01' AND h.ip = '192.168.1.20'
+ON CONFLICT DO NOTHING;
+
+-- printer-01: HTTP, HTTPS, JetDirect
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[80, 443, 9100]) p
+WHERE h.name = 'printer-01' AND h.ip = '192.168.1.50'
+ON CONFLICT DO NOTHING;
+
+-- web-server-01: SSH, HTTP, HTTPS
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 80, 443]) p
+WHERE h.name = 'web-server-01' AND h.ip = '192.168.10.10'
+ON CONFLICT DO NOTHING;
+
+-- web-server-02: SSH, HTTP, HTTPS
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 80, 443]) p
+WHERE h.name = 'web-server-02' AND h.ip = '192.168.10.11'
+ON CONFLICT DO NOTHING;
+
+-- db-server-01: SSH, PostgreSQL
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 5432]) p
+WHERE h.name = 'db-server-01' AND h.ip = '192.168.10.20'
+ON CONFLICT DO NOTHING;
+
+-- mail-server-01: SSH, SMTP, IMAP, SMTPS, Submission, IMAPS
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 25, 143, 465, 587, 993]) p
+WHERE h.name = 'mail-server-01' AND h.ip = '192.168.10.30'
+ON CONFLICT DO NOTHING;
+
+-- core-switch-01: SSH, SNMP
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 161]) p
+WHERE h.name = 'core-switch-01' AND h.ip = '10.0.0.1'
+ON CONFLICT DO NOTHING;
+
+-- monitoring-01: SSH, HTTP, HTTPS, Grafana, Prometheus
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 80, 443, 3000, 9090]) p
+WHERE h.name = 'monitoring-01' AND h.ip = '10.0.1.10'
+ON CONFLICT DO NOTHING;
+
+-- backup-server-01: SSH, SMB, rsync
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 445, 873]) p
+WHERE h.name = 'backup-server-01' AND h.ip = '10.0.1.20'
+ON CONFLICT DO NOTHING;
+
+-- log-server-01: SSH, Syslog, Logstash Beats, Elasticsearch, Kibana
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 514, 5044, 9200, 5601]) p
+WHERE h.name = 'log-server-01' AND h.ip = '10.0.1.30'
+ON CONFLICT DO NOTHING;
+
+-- vpn-gateway-01: SSH, IKE, OpenVPN, IPSec NAT-T
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, p FROM hosts h, unnest(ARRAY[22, 500, 1194, 4500]) p
+WHERE h.name = 'vpn-gateway-01' AND h.ip = '172.16.0.1'
+ON CONFLICT DO NOTHING;
+
+-- vpn clients: SSH only
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, 22 FROM hosts h
+WHERE h.name = 'vpn-client-01' AND h.ip = '172.16.1.10'
+ON CONFLICT DO NOTHING;
+
+INSERT INTO host_ports (host_id, port_number)
+SELECT h.id, 22 FROM hosts h
+WHERE h.name = 'vpn-client-02' AND h.ip = '172.16.1.11'
+ON CONFLICT DO NOTHING;
+
+-- ── Applications ──────────────────────────────────────────────────────────────
+-- applications has no UNIQUE constraint on name, so we use WHERE NOT EXISTS.
+
+INSERT INTO applications (name)
+SELECT v.name FROM (VALUES
+    ('Nginx'),
+    ('Pi-hole'),
+    ('WireGuard'),
+    ('OpenVPN'),
+    ('PostgreSQL'),
+    ('MariaDB'),
+    ('Redis'),
+    ('Grafana'),
+    ('Prometheus'),
+    ('Elasticsearch'),
+    ('Kibana'),
+    ('Portainer'),
+    ('Jellyfin'),
+    ('Home Assistant'),
+    ('Syncthing'),
+    ('Vaultwarden')
+) AS v(name)
+WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = v.name);
+
+-- ── Application ports ─────────────────────────────────────────────────────────
+
+-- Nginx: HTTP, HTTPS
+INSERT INTO application_ports (application_id, port_number) SELECT id, 80  FROM applications WHERE name = 'Nginx' ON CONFLICT DO NOTHING;
+INSERT INTO application_ports (application_id, port_number) SELECT id, 443 FROM applications WHERE name = 'Nginx' ON CONFLICT DO NOTHING;
+
+-- Pi-hole: DNS, HTTP (admin UI), HTTPS
+INSERT INTO application_ports (application_id, port_number) SELECT id, 53  FROM applications WHERE name = 'Pi-hole' ON CONFLICT DO NOTHING;
+INSERT INTO application_ports (application_id, port_number) SELECT id, 80  FROM applications WHERE name = 'Pi-hole' ON CONFLICT DO NOTHING;
+INSERT INTO application_ports (application_id, port_number) SELECT id, 443 FROM applications WHERE name = 'Pi-hole' ON CONFLICT DO NOTHING;
+
+-- WireGuard
+INSERT INTO application_ports (application_id, port_number) SELECT id, 51820 FROM applications WHERE name = 'WireGuard' ON CONFLICT DO NOTHING;
+
+-- OpenVPN
+INSERT INTO application_ports (application_id, port_number) SELECT id, 1194 FROM applications WHERE name = 'OpenVPN' ON CONFLICT DO NOTHING;
+
+-- PostgreSQL
+INSERT INTO application_ports (application_id, port_number) SELECT id, 5432 FROM applications WHERE name = 'PostgreSQL' ON CONFLICT DO NOTHING;
+
+-- MariaDB
+INSERT INTO application_ports (application_id, port_number) SELECT id, 3306 FROM applications WHERE name = 'MariaDB' ON CONFLICT DO NOTHING;
+
+-- Redis
+INSERT INTO application_ports (application_id, port_number) SELECT id, 6379 FROM applications WHERE name = 'Redis' ON CONFLICT DO NOTHING;
+
+-- Grafana
+INSERT INTO application_ports (application_id, port_number) SELECT id, 3000 FROM applications WHERE name = 'Grafana' ON CONFLICT DO NOTHING;
+
+-- Prometheus
+INSERT INTO application_ports (application_id, port_number) SELECT id, 9090 FROM applications WHERE name = 'Prometheus' ON CONFLICT DO NOTHING;
+
+-- Elasticsearch
+INSERT INTO application_ports (application_id, port_number) SELECT id, 9200 FROM applications WHERE name = 'Elasticsearch' ON CONFLICT DO NOTHING;
+
+-- Kibana
+INSERT INTO application_ports (application_id, port_number) SELECT id, 5601 FROM applications WHERE name = 'Kibana' ON CONFLICT DO NOTHING;
+
+-- Portainer: HTTP, HTTPS
+INSERT INTO application_ports (application_id, port_number) SELECT id, 9000 FROM applications WHERE name = 'Portainer' ON CONFLICT DO NOTHING;
+INSERT INTO application_ports (application_id, port_number) SELECT id, 9443 FROM applications WHERE name = 'Portainer' ON CONFLICT DO NOTHING;
+
+-- Jellyfin: HTTP, HTTPS
+INSERT INTO application_ports (application_id, port_number) SELECT id, 8096 FROM applications WHERE name = 'Jellyfin' ON CONFLICT DO NOTHING;
+INSERT INTO application_ports (application_id, port_number) SELECT id, 8920 FROM applications WHERE name = 'Jellyfin' ON CONFLICT DO NOTHING;
+
+-- Home Assistant
+INSERT INTO application_ports (application_id, port_number) SELECT id, 8123 FROM applications WHERE name = 'Home Assistant' ON CONFLICT DO NOTHING;
+
+-- Syncthing: UI, data sync
+INSERT INTO application_ports (application_id, port_number) SELECT id, 8384  FROM applications WHERE name = 'Syncthing' ON CONFLICT DO NOTHING;
+INSERT INTO application_ports (application_id, port_number) SELECT id, 22000 FROM applications WHERE name = 'Syncthing' ON CONFLICT DO NOTHING;
+
+-- Vaultwarden: HTTP, HTTPS
+INSERT INTO application_ports (application_id, port_number) SELECT id, 80  FROM applications WHERE name = 'Vaultwarden' ON CONFLICT DO NOTHING;
+INSERT INTO application_ports (application_id, port_number) SELECT id, 443 FROM applications WHERE name = 'Vaultwarden' ON CONFLICT DO NOTHING;

seeds/sqlite/dev_seed.sql

@@ -40,3 +40,203 @@ INSERT INTO hosts (name, ip, network_id) SELECT 'log-server-01',    '10.0.1.30',
 INSERT INTO hosts (name, ip, network_id) SELECT 'vpn-gateway-01', '172.16.0.1',  id FROM networks WHERE cidr = '172.16.0.0/16'    AND NOT EXISTS (SELECT 1 FROM hosts WHERE name = 'vpn-gateway-01' AND ip = '172.16.0.1');
 INSERT INTO hosts (name, ip, network_id) SELECT 'vpn-client-01',  '172.16.1.10', id FROM networks WHERE cidr = '172.16.0.0/16'    AND NOT EXISTS (SELECT 1 FROM hosts WHERE name = 'vpn-client-01'  AND ip = '172.16.1.10');
 INSERT INTO hosts (name, ip, network_id) SELECT 'vpn-client-02',  '172.16.1.11', id FROM networks WHERE cidr = '172.16.0.0/16'    AND NOT EXISTS (SELECT 1 FROM hosts WHERE name = 'vpn-client-02'  AND ip = '172.16.1.11');
+
+-- ── Ports catalog ─────────────────────────────────────────────────────────────
+
+INSERT OR IGNORE INTO ports (number, description) VALUES
+    (22,    'SSH'),
+    (25,    'SMTP'),
+    (53,    'DNS'),
+    (80,    'HTTP'),
+    (143,   'IMAP'),
+    (161,   'SNMP'),
+    (443,   'HTTPS'),
+    (445,   'SMB'),
+    (465,   'SMTPS'),
+    (500,   'IKE / IPSec'),
+    (514,   'Syslog'),
+    (587,   'SMTP Submission'),
+    (873,   'rsync'),
+    (993,   'IMAPS'),
+    (1194,  'OpenVPN'),
+    (2049,  'NFS'),
+    (3000,  'Grafana / Gitea'),
+    (3306,  'MariaDB / MySQL'),
+    (3389,  'RDP'),
+    (4500,  'IPSec NAT-T'),
+    (5044,  'Logstash Beats'),
+    (5432,  'PostgreSQL'),
+    (5601,  'Kibana'),
+    (6379,  'Redis'),
+    (8096,  'Jellyfin'),
+    (8123,  'Home Assistant'),
+    (8384,  'Syncthing UI'),
+    (8920,  'Jellyfin HTTPS'),
+    (9000,  'Portainer'),
+    (9090,  'Prometheus'),
+    (9100,  'node_exporter / JetDirect'),
+    (9200,  'Elasticsearch'),
+    (9443,  'Portainer HTTPS'),
+    (22000, 'Syncthing'),
+    (51820, 'WireGuard');
+
+-- ── Host ports ────────────────────────────────────────────────────────────────
+-- INSERT OR IGNORE is safe: host_ports has a composite PRIMARY KEY (host_id, port_number).
+-- Host IDs are resolved by subquery on (name, ip) to stay independent of auto-increment values.
+
+-- gateway: SSH, DNS, HTTP (admin UI), HTTPS (admin UI)
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22  FROM hosts WHERE name = 'gateway'        AND ip = '192.168.1.1';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 53  FROM hosts WHERE name = 'gateway'        AND ip = '192.168.1.1';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 80  FROM hosts WHERE name = 'gateway'        AND ip = '192.168.1.1';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 443 FROM hosts WHERE name = 'gateway'        AND ip = '192.168.1.1';
+
+-- workstations: SSH, RDP
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22   FROM hosts WHERE name = 'workstation-01' AND ip = '192.168.1.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 3389 FROM hosts WHERE name = 'workstation-01' AND ip = '192.168.1.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22   FROM hosts WHERE name = 'workstation-02' AND ip = '192.168.1.11';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 3389 FROM hosts WHERE name = 'workstation-02' AND ip = '192.168.1.11';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22   FROM hosts WHERE name = 'workstation-03' AND ip = '192.168.1.12';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 3389 FROM hosts WHERE name = 'workstation-03' AND ip = '192.168.1.12';
+
+-- nas-01: SSH, HTTP (web UI), HTTPS, SMB, NFS
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22   FROM hosts WHERE name = 'nas-01'         AND ip = '192.168.1.20';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 80   FROM hosts WHERE name = 'nas-01'         AND ip = '192.168.1.20';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 443  FROM hosts WHERE name = 'nas-01'         AND ip = '192.168.1.20';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 445  FROM hosts WHERE name = 'nas-01'         AND ip = '192.168.1.20';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 2049 FROM hosts WHERE name = 'nas-01'         AND ip = '192.168.1.20';
+
+-- printer-01: HTTP (web UI), HTTPS, JetDirect
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 80   FROM hosts WHERE name = 'printer-01'     AND ip = '192.168.1.50';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 443  FROM hosts WHERE name = 'printer-01'     AND ip = '192.168.1.50';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 9100 FROM hosts WHERE name = 'printer-01'     AND ip = '192.168.1.50';
+
+-- web servers: SSH, HTTP, HTTPS
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22  FROM hosts WHERE name = 'web-server-01'  AND ip = '192.168.10.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 80  FROM hosts WHERE name = 'web-server-01'  AND ip = '192.168.10.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 443 FROM hosts WHERE name = 'web-server-01'  AND ip = '192.168.10.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22  FROM hosts WHERE name = 'web-server-02'  AND ip = '192.168.10.11';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 80  FROM hosts WHERE name = 'web-server-02'  AND ip = '192.168.10.11';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 443 FROM hosts WHERE name = 'web-server-02'  AND ip = '192.168.10.11';
+
+-- db-server-01: SSH, PostgreSQL
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22   FROM hosts WHERE name = 'db-server-01'   AND ip = '192.168.10.20';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 5432 FROM hosts WHERE name = 'db-server-01'   AND ip = '192.168.10.20';
+
+-- mail-server-01: SSH, SMTP, IMAP, SMTPS, SMTP Submission, IMAPS
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22  FROM hosts WHERE name = 'mail-server-01' AND ip = '192.168.10.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 25  FROM hosts WHERE name = 'mail-server-01' AND ip = '192.168.10.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 143 FROM hosts WHERE name = 'mail-server-01' AND ip = '192.168.10.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 465 FROM hosts WHERE name = 'mail-server-01' AND ip = '192.168.10.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 587 FROM hosts WHERE name = 'mail-server-01' AND ip = '192.168.10.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 993 FROM hosts WHERE name = 'mail-server-01' AND ip = '192.168.10.30';
+
+-- core-switch-01: SSH, SNMP
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22  FROM hosts WHERE name = 'core-switch-01'   AND ip = '10.0.0.1';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 161 FROM hosts WHERE name = 'core-switch-01'   AND ip = '10.0.0.1';
+
+-- monitoring-01: SSH, HTTP, HTTPS, Grafana, Prometheus
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22   FROM hosts WHERE name = 'monitoring-01'    AND ip = '10.0.1.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 80   FROM hosts WHERE name = 'monitoring-01'    AND ip = '10.0.1.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 443  FROM hosts WHERE name = 'monitoring-01'    AND ip = '10.0.1.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 3000 FROM hosts WHERE name = 'monitoring-01'    AND ip = '10.0.1.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 9090 FROM hosts WHERE name = 'monitoring-01'    AND ip = '10.0.1.10';
+
+-- backup-server-01: SSH, SMB, rsync
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22  FROM hosts WHERE name = 'backup-server-01' AND ip = '10.0.1.20';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 445 FROM hosts WHERE name = 'backup-server-01' AND ip = '10.0.1.20';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 873 FROM hosts WHERE name = 'backup-server-01' AND ip = '10.0.1.20';
+
+-- log-server-01: SSH, Syslog, Logstash Beats, Elasticsearch, Kibana
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22   FROM hosts WHERE name = 'log-server-01'    AND ip = '10.0.1.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 514  FROM hosts WHERE name = 'log-server-01'    AND ip = '10.0.1.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 5044 FROM hosts WHERE name = 'log-server-01'    AND ip = '10.0.1.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 9200 FROM hosts WHERE name = 'log-server-01'    AND ip = '10.0.1.30';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 5601 FROM hosts WHERE name = 'log-server-01'    AND ip = '10.0.1.30';
+
+-- vpn-gateway-01: SSH, IKE, IPSec NAT-T, OpenVPN
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22   FROM hosts WHERE name = 'vpn-gateway-01' AND ip = '172.16.0.1';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 500  FROM hosts WHERE name = 'vpn-gateway-01' AND ip = '172.16.0.1';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 1194 FROM hosts WHERE name = 'vpn-gateway-01' AND ip = '172.16.0.1';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 4500 FROM hosts WHERE name = 'vpn-gateway-01' AND ip = '172.16.0.1';
+
+-- vpn clients: SSH only
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22 FROM hosts WHERE name = 'vpn-client-01'  AND ip = '172.16.1.10';
+INSERT OR IGNORE INTO host_ports (host_id, port_number) SELECT id, 22 FROM hosts WHERE name = 'vpn-client-02'  AND ip = '172.16.1.11';
+
+-- ── Applications ──────────────────────────────────────────────────────────────
+-- applications has no UNIQUE constraint on name, so we use WHERE NOT EXISTS.
+
+INSERT INTO applications (name) SELECT 'Nginx'          WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Nginx');
+INSERT INTO applications (name) SELECT 'Pi-hole'        WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Pi-hole');
+INSERT INTO applications (name) SELECT 'WireGuard'      WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'WireGuard');
+INSERT INTO applications (name) SELECT 'OpenVPN'        WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'OpenVPN');
+INSERT INTO applications (name) SELECT 'PostgreSQL'     WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'PostgreSQL');
+INSERT INTO applications (name) SELECT 'MariaDB'        WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'MariaDB');
+INSERT INTO applications (name) SELECT 'Redis'          WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Redis');
+INSERT INTO applications (name) SELECT 'Grafana'        WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Grafana');
+INSERT INTO applications (name) SELECT 'Prometheus'     WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Prometheus');
+INSERT INTO applications (name) SELECT 'Elasticsearch'  WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Elasticsearch');
+INSERT INTO applications (name) SELECT 'Kibana'         WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Kibana');
+INSERT INTO applications (name) SELECT 'Portainer'      WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Portainer');
+INSERT INTO applications (name) SELECT 'Jellyfin'       WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Jellyfin');
+INSERT INTO applications (name) SELECT 'Home Assistant' WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Home Assistant');
+INSERT INTO applications (name) SELECT 'Syncthing'      WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Syncthing');
+INSERT INTO applications (name) SELECT 'Vaultwarden'    WHERE NOT EXISTS (SELECT 1 FROM applications WHERE name = 'Vaultwarden');
+
+-- ── Application ports ─────────────────────────────────────────────────────────
+-- application_ports has a composite PRIMARY KEY, so INSERT OR IGNORE is safe.
+
+-- Nginx: HTTP, HTTPS
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 80  FROM applications WHERE name = 'Nginx';
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 443 FROM applications WHERE name = 'Nginx';
+
+-- Pi-hole: DNS, HTTP (admin UI), HTTPS
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 53  FROM applications WHERE name = 'Pi-hole';
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 80  FROM applications WHERE name = 'Pi-hole';
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 443 FROM applications WHERE name = 'Pi-hole';
+
+-- WireGuard
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 51820 FROM applications WHERE name = 'WireGuard';
+
+-- OpenVPN
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 1194 FROM applications WHERE name = 'OpenVPN';
+
+-- PostgreSQL
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 5432 FROM applications WHERE name = 'PostgreSQL';
+
+-- MariaDB
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 3306 FROM applications WHERE name = 'MariaDB';
+
+-- Redis
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 6379 FROM applications WHERE name = 'Redis';
+
+-- Grafana
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 3000 FROM applications WHERE name = 'Grafana';
+
+-- Prometheus
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 9090 FROM applications WHERE name = 'Prometheus';
+
+-- Elasticsearch
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 9200 FROM applications WHERE name = 'Elasticsearch';
+
+-- Kibana
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 5601 FROM applications WHERE name = 'Kibana';
+
+-- Portainer: HTTP, HTTPS
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 9000 FROM applications WHERE name = 'Portainer';
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 9443 FROM applications WHERE name = 'Portainer';
+
+-- Jellyfin: HTTP, HTTPS
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 8096 FROM applications WHERE name = 'Jellyfin';
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 8920 FROM applications WHERE name = 'Jellyfin';
+
+-- Home Assistant
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 8123 FROM applications WHERE name = 'Home Assistant';
+
+-- Syncthing: UI, data sync
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 8384  FROM applications WHERE name = 'Syncthing';
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 22000 FROM applications WHERE name = 'Syncthing';
+
+-- Vaultwarden: HTTP, HTTPS
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 80  FROM applications WHERE name = 'Vaultwarden';
+INSERT OR IGNORE INTO application_ports (application_id, port_number) SELECT id, 443 FROM applications WHERE name = 'Vaultwarden';

src/api/applications.rs

@@ -1,11 +1,74 @@
 // api/applications.rs — Server functions for applications and their port associations
 
 use leptos::prelude::*;
+use serde::{Deserialize, Serialize};
 
 use crate::models::Application;
 
+// Minimal host reference used by ApplicationDetail.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct HostRef {
+    pub id:   i64,
+    pub name: String,
+    pub ip:   String,
+}
+
+// Full detail for a single application: identity, associated ports, and linked hosts.
+// Linked hosts are those that have at least one port matching an application_ports entry.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct ApplicationDetail {
+    pub id:    i64,
+    pub name:  String,
+    pub ports: Vec<u16>,
+    pub hosts: Vec<HostRef>,
+}
+
+// Application row enriched with the number of hosts that use at least one of
+// its registered ports.  Host count is computed via the join:
+//   application_ports → host_ports (matched on port_number) → hosts
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct ApplicationWithCounts {
+    pub id: i64,
+    pub name: String,
+    /// Distinct hosts that have at least one port matching this application.
+    pub host_count: i64,
+}
+
 // ─── Queries ──────────────────────────────────────────────────────────────────
 
+/// Returns all applications enriched with their associated host count.
+#[server]
+pub async fn get_applications_with_counts() -> Result<Vec<ApplicationWithCounts>, ServerFnError> {
+    use sqlx::{AnyPool, Row};
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    let rows = sqlx::query(
+        "SELECT
+             a.id,
+             a.name,
+             COUNT(DISTINCT hp.host_id) AS host_count
+         FROM applications a
+         LEFT JOIN application_ports ap ON ap.application_id = a.id
+         LEFT JOIN host_ports hp        ON hp.port_number    = ap.port_number
+         GROUP BY a.id, a.name
+         ORDER BY a.name",
+    )
+    .fetch_all(&pool)
+    .await
+    .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    Ok(rows
+        .into_iter()
+        .map(|row| ApplicationWithCounts {
+            id:         row.get("id"),
+            name:       row.get("name"),
+            host_count: row.get("host_count"),
+        })
+        .collect())
+}
+
 /// Returns all applications ordered by name.
 #[server]
 pub async fn get_applications() -> Result<Vec<Application>, ServerFnError> {
@@ -20,6 +83,52 @@ pub async fn get_applications() -> Result<Vec<Application>, ServerFnError> {
         .map_err(|e| ServerFnError::new(e.to_string()))
 }
 
+/// Returns full detail for a single application: identity, ports, and linked hosts.
+///
+/// Linked hosts are hosts that have at least one open port matching one of
+/// the application's registered port numbers (via application_ports ↔ host_ports).
+#[server]
+pub async fn get_application_detail(id: i64) -> Result<ApplicationDetail, ServerFnError> {
+    use sqlx::{AnyPool, Row};
+    use crate::server::repository::applications as repo;
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    let app = repo::find_application(&pool, id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?
+        .ok_or_else(|| ServerFnError::new(format!("Application {id} not found")))?;
+
+    let ports = repo::list_ports_for_application(&pool, id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    let rows = sqlx::query(
+        "SELECT DISTINCT h.id, h.name, h.ip
+         FROM hosts h
+         JOIN host_ports hp        ON hp.host_id    = h.id
+         JOIN application_ports ap ON ap.port_number = hp.port_number
+         WHERE ap.application_id = $1
+         ORDER BY h.name",
+    )
+    .bind(id)
+    .fetch_all(&pool)
+    .await
+    .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    let hosts = rows
+        .iter()
+        .map(|row| HostRef {
+            id:   row.get("id"),
+            name: row.get("name"),
+            ip:   row.get("ip"),
+        })
+        .collect();
+
+    Ok(ApplicationDetail { id: app.id, name: app.name, ports, hosts })
+}
+
 /// Returns the port numbers associated with an application.
 #[server]
 pub async fn get_ports_for_application(
@@ -38,20 +147,55 @@ pub async fn get_ports_for_application(
 
 // ─── Mutations ────────────────────────────────────────────────────────────────
 
-/// Creates a new application and returns the created record.
+/// Updates the name of an application and returns the updated record.
 #[server]
-pub async fn create_application(name: String) -> Result<Application, ServerFnError> {
+pub async fn update_application(id: i64, name: String) -> Result<Application, ServerFnError> {
     use sqlx::AnyPool;
     use crate::server::repository::applications as repo;
 
     let pool = use_context::<AnyPool>()
         .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
 
-    repo::create_application(&pool, &name)
+    if name.trim().is_empty() {
+        return Err(ServerFnError::new("Application name cannot be empty"));
+    }
+
+    repo::update_application(&pool, id, name.trim())
         .await
         .map_err(|e| ServerFnError::new(e.to_string()))
 }
 
+/// Creates a new application, then associates the given port numbers.
+///
+/// `ports` is a comma-separated list of port numbers (e.g. "80,443").
+/// An empty string means no ports are associated.
+#[server]
+pub async fn create_application(name: String, ports: String) -> Result<Application, ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::repository::applications as repo;
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    let app = repo::create_application(&pool, &name)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    let port_numbers: Vec<u16> = ports
+        .split(',')
+        .filter_map(|s| s.trim().parse::<u16>().ok())
+        .filter(|&p| p >= 1)
+        .collect();
+
+    for port_number in port_numbers {
+        repo::add_port_to_application(&pool, app.id, port_number)
+            .await
+            .map_err(|e| ServerFnError::new(e.to_string()))?;
+    }
+
+    Ok(app)
+}
+
 /// Deletes an application and all its port associations.
 ///
 /// Returns `true` if the application existed and was deleted.

src/api/hosts.rs

@@ -3,7 +3,7 @@
 use leptos::prelude::*;
 use serde::{Deserialize, Serialize};
 
-use crate::models::Host;
+use crate::models::{Application, Host, Port};
 
 // ─── Presentation types ───────────────────────────────────────────────────────
 
@@ -30,8 +30,65 @@ pub struct HostsPage {
     pub total_pages: i64, // ceil(total / per_page); always ≥ 1
 }
 
+// Full host detail: identity fields + resolved network + open ports + linked applications.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct HostDetail {
+    pub id: i64,
+    pub name: String,
+    pub ip: String,
+    pub network_id: i64,
+    pub network_name: String,
+    pub network_cidr: String,
+    pub ports: Vec<Port>,
+    pub applications: Vec<Application>,
+}
+
 // ─── Queries ──────────────────────────────────────────────────────────────────
 
+/// Returns full detail for a single host: identity, network, and open ports.
+#[server]
+pub async fn get_host_detail(id: i64) -> Result<HostDetail, ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::repository::{
+        applications as app_repo,
+        hosts as host_repo,
+        networks,
+        ports as port_repo,
+    };
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    let host = host_repo::find_host(&pool, id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?
+        .ok_or_else(|| ServerFnError::new(format!("Host {id} not found")))?;
+
+    let network = networks::find_network(&pool, host.network_id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?
+        .ok_or_else(|| ServerFnError::new(format!("Network {} not found", host.network_id)))?;
+
+    let ports = port_repo::list_ports_for_host(&pool, id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    let applications = app_repo::list_applications_for_host(&pool, id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    Ok(HostDetail {
+        id: host.id,
+        name: host.name,
+        ip: host.ip,
+        network_id: host.network_id,
+        network_name: network.name,
+        network_cidr: network.cidr,
+        ports,
+        applications,
+    })
+}
+
 /// Returns all hosts belonging to a given network.
 #[server]
 pub async fn get_hosts_by_network(network_id: i64) -> Result<Vec<Host>, ServerFnError> {
@@ -48,22 +105,17 @@ pub async fn get_hosts_by_network(network_id: i64) -> Result<Vec<Host>, ServerFn
 
 /// Returns a filtered and paginated list of hosts across all networks.
 ///
-/// Filter parameters use sentinel values (0 / empty string) to mean "no filter":
-///   - `name_filter`            : substring match on host name (case-insensitive); "" = all
-///   - `network_id_filter`      : exact network id; 0 = all
-///   - `port_filter`            : hosts with this port open; 0 = all
-///   - `application_id_filter`  : hosts linked to this application; 0 = all
-///   - `per_page`               : items per page; 0 = return everything
-///   - `page`                   : 1-indexed page number
+/// `port_filter` is a comma-separated list of port numbers (e.g. "80,443").
+/// A host matches only if it has ALL the specified ports open.
+/// An empty string means no port filter.
 ///
-/// The SQL uses each bind parameter twice in the WHERE clause
-/// (once for the IS NULL guard, once for the actual comparison).
-/// Each $N placeholder refers to the N-th bound argument by index.
+/// Port conditions are inlined in the SQL as integer literals (safe: values
+/// are parsed and range-checked before use — no raw user strings are injected).
 #[server]
 pub async fn get_hosts_page(
     name_filter: String,
     network_id_filter: i64,
-    port_filter: i64,
+    port_filter: String,
     application_id_filter: i64,
     page: i64,
     per_page: i64,
@@ -73,47 +125,55 @@ pub async fn get_hosts_page(
     let pool = use_context::<AnyPool>()
         .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
 
-    // Convert sentinel values to Option for SQL NULL binding.
-    // None → binds as SQL NULL → "$N IS NULL" evaluates to TRUE → filter skipped.
     let name_like: Option<String> = if name_filter.is_empty() {
         None
     } else {
         Some(format!("%{}%", name_filter))
     };
     let network_id: Option<i64> = if network_id_filter == 0 { None } else { Some(network_id_filter) };
-    let port: Option<i64>       = if port_filter == 0        { None } else { Some(port_filter) };
     let app_id: Option<i64>     = if application_id_filter == 0 { None } else { Some(application_id_filter) };
 
-    // Each filter param is bound twice so the same $N can appear in both
-    // the IS NULL guard and the comparison without re-declaring parameters.
-    const WHERE: &str = "
-        JOIN networks n ON n.id = h.network_id
-        LEFT JOIN host_ports hp  ON hp.host_id = h.id
-        LEFT JOIN application_ports ap ON ap.port_number = hp.port_number
-        WHERE ($1 IS NULL OR LOWER(h.name) LIKE LOWER($1))
-          AND ($2 IS NULL OR h.network_id = $2)
-          AND ($3 IS NULL OR EXISTS (
-                  SELECT 1 FROM host_ports
-                  WHERE host_id = h.id AND port_number = $3
-              ))
-          AND ($4 IS NULL OR EXISTS (
-                  SELECT 1 FROM host_ports hp2
-                  JOIN application_ports ap2 ON ap2.port_number = hp2.port_number
-                  WHERE hp2.host_id = h.id AND ap2.application_id = $4
-              ))";
+    // Parse and validate port numbers from the CSV string.
+    // Inlined as integer literals in SQL — safe because they are range-checked i64s.
+    let ports: Vec<i64> = port_filter
+        .split(',')
+        .filter_map(|s| s.trim().parse::<i64>().ok())
+        .filter(|&p| p >= 1 && p <= 65535)
+        .collect();
 
-    // Count matching hosts (ignoring pagination).
-    let count_sql = format!("SELECT COUNT(DISTINCT h.id) FROM hosts h {WHERE}");
+    // One EXISTS clause per required port (AND semantics: host must have ALL ports).
+    let port_conditions: String = ports
+        .iter()
+        .map(|p| format!(
+            " AND EXISTS (SELECT 1 FROM host_ports WHERE host_id = h.id AND port_number = {p})"
+        ))
+        .collect();
+
+    // $1 = name_like, $2 = network_id, $3 = app_id
+    // Pagination: $4 = limit, $5 = offset
+    let where_clause = format!(
+        "JOIN networks n ON n.id = h.network_id
+         LEFT JOIN host_ports hp  ON hp.host_id = h.id
+         LEFT JOIN application_ports ap ON ap.port_number = hp.port_number
+         WHERE ($1 IS NULL OR LOWER(h.name) LIKE LOWER($1))
+           AND ($2 IS NULL OR h.network_id = $2)
+           AND ($3 IS NULL OR EXISTS (
+                   SELECT 1 FROM host_ports hp2
+                   JOIN application_ports ap2 ON ap2.port_number = hp2.port_number
+                   WHERE hp2.host_id = h.id AND ap2.application_id = $3
+               ))
+         {port_conditions}"
+    );
+
+    let count_sql = format!("SELECT COUNT(DISTINCT h.id) FROM hosts h {where_clause}");
     let total: i64 = sqlx::query_scalar(&count_sql)
         .bind(name_like.as_deref())
         .bind(network_id)
-        .bind(port)
         .bind(app_id)
         .fetch_one(&pool)
         .await
         .map_err(|e| ServerFnError::new(e.to_string()))?;
 
-    // Compute pagination bounds.
     let safe_page = page.max(1);
     let (limit, offset, total_pages) = if per_page <= 0 {
         (1_000_000_000i64, 0i64, 1i64)
@@ -122,23 +182,21 @@ pub async fn get_hosts_page(
         (per_page, (safe_page - 1) * per_page, tp)
     };
 
-    // Fetch the page of hosts with enriched columns.
     let data_sql = format!(
         "SELECT h.id, h.name, h.ip, h.network_id,
                 n.cidr AS network_cidr,
                 COUNT(DISTINCT hp.port_number)      AS port_count,
                 COUNT(DISTINCT ap.application_id)   AS application_count
          FROM hosts h
-         {WHERE}
+         {where_clause}
          GROUP BY h.id, h.name, h.ip, h.network_id, n.cidr
          ORDER BY h.name, h.id
-         LIMIT $5 OFFSET $6"
+         LIMIT $4 OFFSET $5"
     );
 
     let rows = sqlx::query(&data_sql)
         .bind(name_like.as_deref())
         .bind(network_id)
-        .bind(port)
         .bind(app_id)
         .bind(limit)
         .bind(offset)
@@ -170,19 +228,21 @@ pub async fn get_hosts_page(
 
 // ─── Mutations ────────────────────────────────────────────────────────────────
 
-/// Creates a new host inside the specified network.
+/// Creates a new host inside the specified network, then opens the given ports.
 ///
-/// Validates that `ip` falls within the CIDR of `network_id`.
-/// Returns an error if the network does not exist or the IP is out of range.
+/// `ports` is a comma-separated list of port numbers (e.g. "22,80,443").
+/// Ports are auto-registered in the global catalog if not already present.
+/// An empty string means no ports are opened.
 #[server]
 pub async fn create_host(
     name: String,
     ip: String,
     network_id: i64,
+    ports: String,
 ) -> Result<Host, ServerFnError> {
     use sqlx::AnyPool;
     use crate::server::{
-        repository::{hosts, networks},
+        repository::{hosts, networks, ports as port_repo},
         validation::validate_ip_in_network,
     };
 
@@ -192,14 +252,168 @@ pub async fn create_host(
     let network = networks::find_network(&pool, network_id)
         .await
         .map_err(|e| ServerFnError::new(e.to_string()))?
-        .ok_or_else(|| {
-            ServerFnError::new(format!("Network {network_id} not found"))
-        })?;
+        .ok_or_else(|| ServerFnError::new(format!("Network {network_id} not found")))?;
 
     validate_ip_in_network(&ip, &network.cidr)
         .map_err(|e| ServerFnError::new(e.to_string()))?;
 
-    hosts::create_host(&pool, &name, &ip, network_id)
+    let host = hosts::create_host(&pool, &name, &ip, network_id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    // Parse, validate, and open each port on the new host.
+    let port_numbers: Vec<u16> = ports
+        .split(',')
+        .filter_map(|s| s.trim().parse::<u16>().ok())
+        .filter(|&p| p >= 1)
+        .collect();
+
+    for port_number in port_numbers {
+        port_repo::add_port_to_host(&pool, host.id, port_number)
+            .await
+            .map_err(|e| ServerFnError::new(e.to_string()))?;
+    }
+
+    Ok(host)
+}
+
+/// Updates a host's name, IP address, and network assignment.
+///
+/// Validates that the new IP falls within the CIDR of the new network.
+#[server]
+pub async fn update_host(
+    id: i64,
+    name: String,
+    ip: String,
+    network_id: i64,
+) -> Result<Host, ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::{
+        repository::{hosts as host_repo, networks},
+        validation::validate_ip_in_network,
+    };
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    if name.trim().is_empty() {
+        return Err(ServerFnError::new("Name must not be empty"));
+    }
+
+    let network = networks::find_network(&pool, network_id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?
+        .ok_or_else(|| ServerFnError::new(format!("Network {network_id} not found")))?;
+
+    validate_ip_in_network(&ip, &network.cidr)
+        .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    host_repo::update_host(&pool, id, name.trim(), ip.trim(), network_id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?
+        .ok_or_else(|| ServerFnError::new(format!("Host {id} not found")))
+}
+
+/// Opens a single port on a host.
+///
+/// Auto-registers the port in the global catalog if not already present.
+/// If the port is already open on this host, the call is a no-op.
+#[server]
+pub async fn add_host_port(host_id: i64, port_number: i64) -> Result<(), ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::repository::ports as port_repo;
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    if !(1..=65535).contains(&port_number) {
+        return Err(ServerFnError::new("Port number must be between 1 and 65535"));
+    }
+
+    port_repo::add_port_to_host(&pool, host_id, port_number as u16)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))
+}
+
+/// Closes a port on a host (removes the host-port association).
+///
+/// The port entry in the global catalog is not deleted.
+/// If the port was not open on this host, the call is a no-op.
+#[server]
+pub async fn remove_host_port(host_id: i64, port_number: i64) -> Result<(), ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::repository::ports as port_repo;
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    port_repo::remove_port_from_host(&pool, host_id, port_number as u16)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))
+}
+
+/// Returns all applications not yet directly linked to a host.
+///
+/// Used to populate the "add applications" modal on the host detail page.
+#[server]
+pub async fn get_applications_not_on_host(
+    host_id: i64,
+) -> Result<Vec<Application>, ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::repository::applications as repo;
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    repo::list_applications_not_on_host(&pool, host_id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))
+}
+
+/// Links one or more applications to a host.
+///
+/// `application_ids` is a comma-separated string of application IDs (e.g. "1,3,7").
+/// Already-linked applications are silently skipped (no-op).
+#[server]
+pub async fn add_host_applications(
+    host_id: i64,
+    application_ids: String,
+) -> Result<(), ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::repository::applications as repo;
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    let ids: Vec<i64> = application_ids
+        .split(',')
+        .filter_map(|s| s.trim().parse::<i64>().ok())
+        .collect();
+
+    for application_id in ids {
+        repo::add_application_to_host(&pool, host_id, application_id)
+            .await
+            .map_err(|e| ServerFnError::new(e.to_string()))?;
+    }
+
+    Ok(())
+}
+
+/// Removes the direct link between a host and an application.
+///
+/// Returns `true` if the association existed and was removed.
+#[server]
+pub async fn remove_host_application(
+    host_id: i64,
+    application_id: i64,
+) -> Result<bool, ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::repository::applications as repo;
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    repo::remove_application_from_host(&pool, host_id, application_id)
         .await
         .map_err(|e| ServerFnError::new(e.to_string()))
 }

src/api/networks.rs

@@ -77,6 +77,21 @@ pub async fn get_networks_with_counts() -> Result<Vec<NetworkWithCounts>, Server
     Ok(networks)
 }
 
+/// Returns a single network by id, or an error if it does not exist.
+#[server]
+pub async fn get_network(id: i64) -> Result<Network, ServerFnError> {
+    use sqlx::AnyPool;
+    use crate::server::repository::networks as repo;
+
+    let pool = use_context::<AnyPool>()
+        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;
+
+    repo::find_network(&pool, id)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?
+        .ok_or_else(|| ServerFnError::new(format!("Network {id} not found")))
+}
+
 // ─── Mutations ────────────────────────────────────────────────────────────────
 
 /// Creates a new network with the given name and CIDR block.

src/app.rs

@@ -11,7 +11,16 @@ use leptos_router::{
     path,
 };
 
-use crate::client::{home::HomePage, hosts::HostsPage, networks::NetworksPage, theme::ThemeToggle};
+use crate::client::{
+    application_detail::ApplicationDetailPage,
+    applications::ApplicationsPage,
+    home::HomePage,
+    host_detail::HostDetailPage,
+    hosts::HostsPage,
+    network_detail::NetworkDetailPage,
+    networks::NetworksPage,
+    theme::ThemeToggle,
+};
 
 // Shell — full HTML document rendered by the Axum server.
 //
@@ -87,6 +96,7 @@ pub fn App() -> impl IntoView {
                 <a href="/">"Rust IPAM"</a>
                 <a href="/networks">"Networks"</a>
                 <a href="/hosts">"Hosts"</a>
+                <a href="/applications">"Applications"</a>
                 <span class="nav-spacer"/>
                 <ThemeToggle/>
             </nav>
@@ -102,7 +112,11 @@ pub fn App() -> impl IntoView {
                 }>
                     <Route path=path!("/") view=HomePage/>
                     <Route path=path!("/networks") view=NetworksPage/>
+                    <Route path=path!("/networks/:id") view=NetworkDetailPage/>
                     <Route path=path!("/hosts") view=HostsPage/>
+                    <Route path=path!("/hosts/:id") view=HostDetailPage/>
+                    <Route path=path!("/applications") view=ApplicationsPage/>
+                    <Route path=path!("/applications/:id") view=ApplicationDetailPage/>
                 </Routes>
             </main>
         </Router>

src/bin/seed.rs

@@ -85,5 +85,13 @@ async fn main() {
         .await
         .unwrap_or(0);
 
-    tracing::info!("Database now contains {} network(s) and {} host(s).", network_count, host_count);
+    let application_count: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM applications")
+        .fetch_one(&pool)
+        .await
+        .unwrap_or(0);
+
+    tracing::info!(
+        "Database now contains {} network(s), {} host(s) and {} application(s).",
+        network_count, host_count, application_count
+    );
 }

src/client/application_detail.rs

@@ -0,0 +1,311 @@
+// client/application_detail.rs — Application detail page
+//
+// Shows all information for a single application:
+//   - Identity form  : name — editable, saved with "Save changes"
+//   - Ports section  : ports associated with this application + Add/Remove per port
+//   - Hosts section  : hosts sharing at least one port with this application (read-only)
+//   - Delete button  : confirmation modal, then navigates back to /applications
+
+use leptos::prelude::*;
+use leptos_router::hooks::{use_navigate, use_params_map, use_query_map};
+
+use crate::api::applications::{
+    AddPortToApplication, DeleteApplication, RemovePortFromApplication,
+    UpdateApplication, get_application_detail,
+};
+
+// ─── Delete confirmation modal ────────────────────────────────────────────────
+
+#[component]
+fn DeleteModal(
+    app_name: String,
+    delete_action: ServerAction<DeleteApplication>,
+    app_id: i64,
+    show_modal: RwSignal<bool>,
+) -> impl IntoView {
+    view! {
+        <div class="modal-backdrop" on:click=move |_| show_modal.set(false)>
+            <div class="modal" on:click=move |e| e.stop_propagation()>
+                <div class="modal__header">
+                    <h2>"Delete application"</h2>
+                    <button class="modal__close" type="button" aria-label="Close"
+                        on:click=move |_| show_modal.set(false)>
+                        "×"
+                    </button>
+                </div>
+                <div class="modal__body">
+                    <p class="warning">
+                        "Are you sure you want to delete "
+                        <strong>{app_name}</strong>
+                        "? All port associations will also be removed."
+                    </p>
+                </div>
+                <div class="modal__actions">
+                    <button class="btn-secondary" type="button"
+                        on:click=move |_| show_modal.set(false)>
+                        "Cancel"
+                    </button>
+                    <button class="btn-danger" type="button"
+                        on:click=move |_| { delete_action.dispatch(DeleteApplication { id: app_id }); }>
+                        "Delete"
+                    </button>
+                </div>
+            </div>
+        </div>
+    }.into_any()
+}
+
+// ─── Main page component ──────────────────────────────────────────────────────
+
+#[component]
+pub fn ApplicationDetailPage() -> impl IntoView {
+    let params = use_params_map();
+    let app_id = move || {
+        params.read().get("id")
+            .and_then(|s| s.parse::<i64>().ok())
+            .unwrap_or(0)
+    };
+
+    let query = use_query_map();
+    let back_url = move || {
+        query.read().get("back")
+            .map(|s| s.to_string())
+            .unwrap_or_else(|| "/applications".to_string())
+    };
+    let back_label = move || {
+        if back_url().starts_with("/hosts/") { "← Host" } else { "← Applications" }
+    };
+
+    let update_action      = ServerAction::<UpdateApplication>::new();
+    let add_port_action    = ServerAction::<AddPortToApplication>::new();
+    let remove_port_action = ServerAction::<RemovePortFromApplication>::new();
+    let delete_action      = ServerAction::<DeleteApplication>::new();
+
+    let show_delete_modal = RwSignal::new(false);
+
+    let app = LocalResource::new(move || {
+        let _ = update_action.version().get();
+        let _ = add_port_action.version().get();
+        let _ = remove_port_action.version().get();
+        get_application_detail(app_id())
+    });
+
+    let name_sig = RwSignal::new(String::new());
+    let new_port = RwSignal::new(String::new());
+
+    // Sync the editable name whenever fresh data arrives.
+    Effect::new(move |_| {
+        if let Some(r) = app.get() {
+            if let Ok(ref detail) = *r {
+                name_sig.set(detail.name.clone());
+            }
+        }
+    });
+
+    let navigate = use_navigate();
+    Effect::new(move |_| {
+        if let Some(Ok(true)) = delete_action.value().get() {
+            navigate("/applications", Default::default());
+        }
+    });
+
+    view! {
+        <div class="application-detail-page">
+            // Delete modal lives OUTSIDE <Suspense> so it is not unmounted when
+            // the application resource re-fetches.
+            {move || show_delete_modal.get().then(|| view! {
+                <DeleteModal
+                    app_name=name_sig.get()
+                    delete_action=delete_action
+                    app_id=app_id()
+                    show_modal=show_delete_modal
+                />
+            })}
+
+            <Suspense fallback=|| view! { <p class="empty">"Loading application…"</p> }>
+                {move || app.get().map(|r| match (*r).clone() {
+                    Err(e) => view! {
+                        <p class="error">"Could not load application: " {e.to_string()}</p>
+                    }.into_any(),
+
+                    Ok(detail) => {
+                        let id         = detail.id;
+                        let port_count = detail.ports.len();
+                        let host_count = detail.hosts.len();
+                        let ports      = detail.ports;
+                        let hosts      = detail.hosts;
+
+                        let ports_list = if ports.is_empty() {
+                            view! {
+                                <p class="empty">"No ports associated with this application."</p>
+                            }.into_any()
+                        } else {
+                            view! {
+                                <div class="port-list">
+                                    {ports.into_iter().map(|num| {
+                                        view! {
+                                            <div class="port-row">
+                                                <span class="port-row__number">{num}</span>
+                                                <button
+                                                    class="btn-danger"
+                                                    type="button"
+                                                    on:click=move |_| {
+                                                        remove_port_action.dispatch(
+                                                            RemovePortFromApplication {
+                                                                application_id: id,
+                                                                port_number: num,
+                                                            }
+                                                        );
+                                                    }
+                                                >
+                                                    "Remove"
+                                                </button>
+                                            </div>
+                                        }
+                                    }).collect_view()}
+                                </div>
+                            }.into_any()
+                        };
+
+                        let hosts_list = if hosts.is_empty() {
+                            view! {
+                                <p class="empty">"No hosts share a port with this application."</p>
+                            }.into_any()
+                        } else {
+                            view! {
+                                <div class="app-list">
+                                    {hosts.into_iter().map(|host| {
+                                        view! {
+                                            <div class="app-row">
+                                                <a class="table-link"
+                                                    href=format!("/hosts/{}?back=/applications/{}", host.id, id)>
+                                                    {host.name}
+                                                </a>
+                                                <span class="cell-mono">{host.ip}</span>
+                                            </div>
+                                        }
+                                    }).collect_view()}
+                                </div>
+                            }.into_any()
+                        };
+
+                        view! {
+                            // ── Page header ───────────────────────────────────
+                            <div class="page-header detail-page-header">
+                                <a class="back-btn" href=move || back_url()>
+                                    {move || back_label()}
+                                </a>
+                                <h1 class="detail-page-title">{move || name_sig.get()}</h1>
+                            </div>
+
+                            // ── Identity form ─────────────────────────────────
+                            <section class="detail-section">
+                                <h2 class="detail-section__title">"Identity"</h2>
+                                <div class="detail-form">
+                                    <label class="detail-field">
+                                        "Name"
+                                        <input
+                                            type="text"
+                                            prop:value=move || name_sig.get()
+                                            on:input=move |e| name_sig.set(event_target_value(&e))
+                                        />
+                                    </label>
+
+                                    {move || update_action.value().get()
+                                        .and_then(|r| r.err())
+                                        .map(|e| view! { <p class="error">{e.to_string()}</p> })
+                                    }
+
+                                    <div class="form-actions">
+                                        <button
+                                            class="btn-primary"
+                                            type="button"
+                                            on:click=move |_| {
+                                                update_action.dispatch(UpdateApplication {
+                                                    id,
+                                                    name: name_sig.get_untracked(),
+                                                });
+                                            }
+                                        >
+                                            "Save changes"
+                                        </button>
+                                    </div>
+                                </div>
+                            </section>
+
+                            // ── Ports section ─────────────────────────────────
+                            <section class="detail-section">
+                                <h2 class="detail-section__title">
+                                    {format!("Associated ports ({})", port_count)}
+                                </h2>
+
+                                {ports_list}
+
+                                {move || remove_port_action.value().get()
+                                    .and_then(|r| r.err())
+                                    .map(|e| view! {
+                                        <p class="error">"Remove failed: " {e.to_string()}</p>
+                                    })
+                                }
+
+                                <div class="port-add-row">
+                                    <input
+                                        type="number"
+                                        min="1"
+                                        max="65535"
+                                        placeholder="Port number (1–65535)"
+                                        prop:value=move || new_port.get()
+                                        on:input=move |e| new_port.set(event_target_value(&e))
+                                    />
+                                    <button
+                                        class="btn-primary"
+                                        type="button"
+                                        on:click=move |_| {
+                                            let raw = new_port.get_untracked();
+                                            if let Ok(n) = raw.trim().parse::<i64>() {
+                                                if (1..=65535).contains(&n) {
+                                                    add_port_action.dispatch(AddPortToApplication {
+                                                        application_id: id,
+                                                        port_number: n as u16,
+                                                    });
+                                                    new_port.set(String::new());
+                                                }
+                                            }
+                                        }
+                                    >
+                                        "Add port"
+                                    </button>
+                                    {move || add_port_action.value().get()
+                                        .and_then(|r| r.err())
+                                        .map(|e| view! {
+                                            <p class="error">"Add failed: " {e.to_string()}</p>
+                                        })
+                                    }
+                                </div>
+                            </section>
+
+                            // ── Hosts section (read-only — linked via shared ports) ──
+                            <section class="detail-section">
+                                <h2 class="detail-section__title">
+                                    {format!("Linked hosts ({})", host_count)}
+                                </h2>
+                                {hosts_list}
+                            </section>
+
+                            // ── Danger zone ───────────────────────────────────
+                            <div class="danger-zone">
+                                <button
+                                    class="btn-danger-solid"
+                                    type="button"
+                                    on:click=move |_| show_delete_modal.set(true)
+                                >
+                                    "Delete application"
+                                </button>
+                            </div>
+                        }.into_any()
+                    }
+                })}
+            </Suspense>
+        </div>
+    }.into_any()
+}

src/client/applications.rs

@@ -0,0 +1,294 @@
+// client/applications.rs — Applications list page
+//
+// Displays all applications with:
+//   - Add button  : opens a modal to create an application by name
+//   - Filter bar  : name substring filter (client-side)
+//   - Table       : application name + number of associated hosts
+//   - Delete      : confirmation modal before deletion
+
+use leptos::prelude::*;
+use leptos::form::ActionForm;
+use leptos::html::Input;
+
+use crate::api::applications::{
+    ApplicationWithCounts, CreateApplication, DeleteApplication,
+    get_applications_with_counts,
+};
+
+// ─── Add application modal ────────────────────────────────────────────────────
+
+#[component]
+fn AddApplicationModal(
+    create_action: ServerAction<CreateApplication>,
+    show_modal: RwSignal<bool>,
+) -> impl IntoView {
+    use leptos::task::spawn_local;
+
+    let name_ref = NodeRef::<Input>::new();
+
+    // Defer focus to the next microtask so the element is in the DOM.
+    // Using get_untracked() avoids subscribing to NodeRef's reactive signal,
+    // which would otherwise re-trigger during modal unmount and cause
+    // "closure invoked after being dropped" in wasm-bindgen.
+    spawn_local(async move {
+        if let Some(el) = name_ref.get_untracked() {
+            let _ = el.focus();
+        }
+    });
+
+    // close() defers show_modal.set(false) to the next microtask.
+    // Without this, setting the signal synchronously inside a click handler
+    // unmounts the modal (and frees its closures) while the handler is still
+    // on the call stack, causing wasm-bindgen to panic.
+    let close = move || spawn_local(async move { show_modal.set(false) });
+
+    view! {
+        <div class="modal-backdrop" on:click=move |_| close()>
+            <div class="modal" on:click=move |e| e.stop_propagation()>
+                <div class="modal__header">
+                    <h2>"Add an application"</h2>
+                    <button class="modal__close" type="button" aria-label="Close"
+                        on:click=move |_| close()>
+                        "×"
+                    </button>
+                </div>
+
+                <ActionForm action=create_action>
+                    <div class="add-form__fields">
+                        <label>
+                            "Name"
+                            <input
+                                node_ref=name_ref
+                                type="text"
+                                name="name"
+                                placeholder="e.g. Nginx, PostgreSQL, Prometheus"
+                                required
+                            />
+                        </label>
+                        <label>
+                            "Associated ports"
+                            <input
+                                type="text"
+                                name="ports"
+                                placeholder="e.g. 22, 80, 443"
+                            />
+                            <span class="field-hint">"Comma-separated port numbers"</span>
+                        </label>
+                    </div>
+
+                    <div class="modal__actions">
+                        <button class="btn-secondary" type="button"
+                            on:click=move |_| close()>
+                            "Cancel"
+                        </button>
+                        <button type="submit">"Add application"</button>
+                    </div>
+                </ActionForm>
+
+                {move || create_action.value().get()
+                    .and_then(|r| r.err())
+                    .map(|e| view! { <p class="error">{e.to_string()}</p> })
+                }
+            </div>
+        </div>
+    }.into_any()
+}
+
+// ─── Delete confirmation modal ────────────────────────────────────────────────
+
+#[component]
+fn DeleteAppModal(
+    app: ApplicationWithCounts,
+    delete_action: ServerAction<DeleteApplication>,
+    pending_delete: RwSignal<Option<ApplicationWithCounts>>,
+) -> impl IntoView {
+    let id         = app.id;
+    let label      = app.name.clone();
+    let host_count = app.host_count;
+
+    view! {
+        <div class="modal-backdrop" on:click=move |_| pending_delete.set(None)>
+            <div class="modal" on:click=move |e| e.stop_propagation()>
+                <div class="modal__header">
+                    <h2>"Delete application"</h2>
+                    <button class="modal__close" type="button" aria-label="Close"
+                        on:click=move |_| pending_delete.set(None)>
+                        "×"
+                    </button>
+                </div>
+                <div class="modal__body">
+                    <p>"Delete application " <strong>{label}</strong> "?"</p>
+                    {(host_count > 0).then(|| view! {
+                        <p class="warning">
+                            "This application is linked to "
+                            {host_count}
+                            {if host_count == 1 { " host" } else { " hosts" }}
+                            " via shared ports. The port associations will be removed."
+                        </p>
+                    })}
+                </div>
+                <div class="modal__actions">
+                    <button class="btn-secondary" type="button"
+                        on:click=move |_| pending_delete.set(None)>
+                        "Cancel"
+                    </button>
+                    <button class="btn-danger" type="button"
+                        on:click=move |_| { delete_action.dispatch(DeleteApplication { id }); }>
+                        "Delete"
+                    </button>
+                </div>
+            </div>
+        </div>
+    }.into_any()
+}
+
+// ─── Page ─────────────────────────────────────────────────────────────────────
+
+#[component]
+pub fn ApplicationsPage() -> impl IntoView {
+    let create_action = ServerAction::<CreateApplication>::new();
+    let delete_action = ServerAction::<DeleteApplication>::new();
+
+    let show_modal = RwSignal::new(false);
+
+    // Some(app) = delete modal open for that app; None = closed.
+    let pending_delete: RwSignal<Option<ApplicationWithCounts>> = RwSignal::new(None);
+
+    // Name filter (client-side — list is typically small)
+    let name_filter = RwSignal::new(String::new());
+
+    // Close the add modal when the action transitions pending→done with Ok.
+    // Lives in the parent so it is never recreated across modal open/close cycles,
+    // which avoids the stale-value re-trigger bug.
+    Effect::new(move |was_pending: Option<bool>| {
+        let is_pending = create_action.pending().get();
+        if was_pending == Some(true) && !is_pending {
+            if let Some(Ok(_)) = create_action.value().get() {
+                show_modal.set(false);
+            }
+        }
+        is_pending
+    });
+
+    // Close the delete modal automatically after a successful deletion.
+    Effect::new(move |_| {
+        if let Some(Ok(_)) = delete_action.value().get() {
+            pending_delete.set(None);
+        }
+    });
+
+    let applications = Resource::new(
+        move || (create_action.version().get(), delete_action.version().get()),
+        |_| get_applications_with_counts(),
+    );
+
+    view! {
+        <div class="applications-page">
+
+            // ── Page header ───────────────────────────────────────────────────
+            <div class="page-header">
+                <h1>"Applications"</h1>
+                <button class="btn-primary" on:click=move |_| show_modal.set(true)>
+                    "+ Add application"
+                </button>
+            </div>
+
+            // ── Add modal ─────────────────────────────────────────────────────
+            {move || show_modal.get().then(|| view! {
+                <AddApplicationModal
+                    create_action=create_action
+                    show_modal=show_modal
+                />
+            })}
+
+            // ── Delete modal ──────────────────────────────────────────────────
+            {move || pending_delete.get().map(|app| view! {
+                <DeleteAppModal
+                    app=app
+                    delete_action=delete_action
+                    pending_delete=pending_delete
+                />
+            })}
+
+            // ── Filter bar ────────────────────────────────────────────────────
+            <section class="filter-bar">
+                <div class="filter-bar__fields">
+                    <label class="filter-field">
+                        "Name"
+                        <input
+                            type="text"
+                            placeholder="Search…"
+                            on:input=move |e| name_filter.set(event_target_value(&e))
+                        />
+                    </label>
+                </div>
+            </section>
+
+            // ── Application list ──────────────────────────────────────────────
+            <section class="list">
+                {move || delete_action.value().get()
+                    .and_then(|r| r.err())
+                    .map(|e| view! { <p class="error">"Delete failed: " {e.to_string()}</p> })
+                }
+
+                <Suspense fallback=|| view! { <p>"Loading applications…"</p> }>
+                    {move || applications.get().map(|result| match result {
+                        Err(e) => view! {
+                            <p class="error">"Could not load applications: " {e.to_string()}</p>
+                        }.into_any(),
+
+                        Ok(list) => {
+                            let filter = name_filter.get().to_lowercase();
+                            let filtered: Vec<_> = list.into_iter()
+                                .filter(|app| filter.is_empty() || app.name.to_lowercase().contains(&filter))
+                                .collect();
+
+                            if filtered.is_empty() {
+                                view! {
+                                    <p class="empty">"No applications match the current filter."</p>
+                                }.into_any()
+                            } else {
+                                view! {
+                                    <div class="table-container">
+                                        <table>
+                                            <thead>
+                                                <tr>
+                                                    <th>"Name"</th>
+                                                    <th class="col-count">"Hosts"</th>
+                                                    <th class="col-actions">"Actions"</th>
+                                                </tr>
+                                            </thead>
+                                            <tbody>
+                                                {filtered.into_iter().map(|app| {
+                                                    let app_clone = app.clone();
+                                                    view! {
+                                                        <tr>
+                                                            <td>
+                                                                <a class="table-link"
+                                                                    href=format!("/applications/{}", app.id)>
+                                                                    {app.name}
+                                                                </a>
+                                                            </td>
+                                                            <td class="col-count">{app.host_count}</td>
+                                                            <td class="col-actions">
+                                                                <button class="btn-danger" on:click=move |_| {
+                                                                    pending_delete.set(Some(app_clone.clone()));
+                                                                }>
+                                                                    "Delete"
+                                                                </button>
+                                                            </td>
+                                                        </tr>
+                                                    }
+                                                }).collect_view()}
+                                            </tbody>
+                                        </table>
+                                    </div>
+                                }.into_any()
+                            }
+                        }
+                    })}
+                </Suspense>
+            </section>
+        </div>
+    }
+}

src/client/host_detail.rs

@@ -0,0 +1,585 @@
+// client/host_detail.rs — Host detail page
+//
+// Shows all information for a single host:
+//   - Identity form     : name, IP, network dropdown — editable, saved with "Save changes"
+//   - Ports section     : full list with Remove per port + Add port input
+//   - Applications      : directly linked apps with Remove + modal multi-select to add
+//   - Delete button     : opens a confirmation modal, then navigates back to /hosts
+
+use leptos::prelude::*;
+use leptos_router::hooks::{use_navigate, use_params_map, use_query_map};
+
+use crate::api::{
+    hosts::{
+        AddHostApplications, AddHostPort, DeleteHost, RemoveHostApplication,
+        RemoveHostPort, UpdateHost, get_applications_not_on_host, get_host_detail,
+    },
+    networks::get_networks,
+};
+use crate::models::Application;
+
+// ─── Add applications modal ───────────────────────────────────────────────────
+
+// Scrollable pick list + selected tags:
+//   - Top: scrollable list of available apps; clicking one moves it to the
+//     selected section and removes it from the list.
+//   - Bottom: selected apps shown as removable tags; clicking × puts the app
+//     back in the list.
+//
+// The auto-close Effect lives in the PARENT to avoid the re-trigger bug
+// (an Effect inside a conditionally-rendered component fires on mount and
+// would immediately close the modal if the action already held a past Ok value).
+#[component]
+fn AddAppModal(
+    host_id: i64,
+    available_apps_res: LocalResource<Result<Vec<Application>, ServerFnError>>,
+    add_action: ServerAction<AddHostApplications>,
+    show_modal: RwSignal<bool>,
+) -> impl IntoView {
+    // Full Application structs so names are available in the selected tag list.
+    let selected: RwSignal<Vec<Application>> = RwSignal::new(vec![]);
+
+    view! {
+        <div class="modal-backdrop" on:click=move |_| show_modal.set(false)>
+            <div class="modal" on:click=move |e| e.stop_propagation()>
+                <div class="modal__header">
+                    <h2>"Add applications"</h2>
+                    <button class="modal__close" type="button" aria-label="Close"
+                        on:click=move |_| show_modal.set(false)>
+                        "×"
+                    </button>
+                </div>
+
+                <div class="modal__body">
+
+                    // ── Scrollable pick list ──────────────────────────────────
+                    {move || match available_apps_res.get() {
+                        None => view! { <p class="empty">"Loading…"</p> }.into_any(),
+                        Some(r) => match (*r).clone() {
+                            Err(e) => view! {
+                                <p class="error">
+                                    "Could not load applications: " {e.to_string()}
+                                </p>
+                            }.into_any(),
+                            Ok(apps) => {
+                                // Exclude already-selected apps from the displayed list.
+                                let sel_ids: Vec<i64> = selected.get()
+                                    .iter().map(|a| a.id).collect();
+                                let displayed: Vec<Application> = apps.into_iter()
+                                    .filter(|a| !sel_ids.contains(&a.id))
+                                    .collect();
+
+                                if displayed.is_empty() && sel_ids.is_empty() {
+                                    view! {
+                                        <p class="empty">
+                                            "All applications are already linked to this host."
+                                        </p>
+                                    }.into_any()
+                                } else if displayed.is_empty() {
+                                    view! {
+                                        <p class="empty">
+                                            "All available applications have been selected."
+                                        </p>
+                                    }.into_any()
+                                } else {
+                                    view! {
+                                        <ul class="app-pick-list">
+                                            {displayed.into_iter().map(|app| {
+                                                let app_clone = app.clone();
+                                                view! {
+                                                    <li class="app-pick-item"
+                                                        on:click=move |_| {
+                                                            selected.update(|v| {
+                                                                v.push(app_clone.clone());
+                                                            });
+                                                        }
+                                                    >
+                                                        <span>{app.name}</span>
+                                                        <span class="app-pick-item__add">"+"</span>
+                                                    </li>
+                                                }
+                                            }).collect_view()}
+                                        </ul>
+                                    }.into_any()
+                                }
+                            }
+                        }
+                    }}
+
+                    // ── Selected tags (shown once at least one app is chosen) ─
+                    {move || (!selected.get().is_empty()).then(|| {
+                        let sel = selected.get();
+                        view! {
+                            <div class="app-selected-section">
+                                <span class="app-selected-label">"Selected:"</span>
+                                <div class="app-selected-list">
+                                    {sel.into_iter().map(|app| {
+                                        let app_id = app.id;
+                                        view! {
+                                            <span class="app-selected-tag">
+                                                {app.name}
+                                                <button
+                                                    class="app-selected-tag__remove"
+                                                    type="button"
+                                                    aria-label="Remove"
+                                                    on:click=move |_| {
+                                                        selected.update(|v| {
+                                                            v.retain(|x| x.id != app_id);
+                                                        });
+                                                    }
+                                                >"×"</button>
+                                            </span>
+                                        }
+                                    }).collect_view()}
+                                </div>
+                            </div>
+                        }
+                    })}
+
+                    {move || add_action.value().get()
+                        .and_then(|r| r.err())
+                        .map(|e| view! { <p class="error">{e.to_string()}</p> })
+                    }
+                </div>
+
+                <div class="modal__actions">
+                    <button class="btn-secondary" type="button"
+                        on:click=move |_| show_modal.set(false)>
+                        "Cancel"
+                    </button>
+                    <button
+                        class="btn-primary"
+                        type="button"
+                        disabled={move || selected.get().is_empty()}
+                        on:click=move |_| {
+                            let ids_str = selected.get_untracked()
+                                .iter()
+                                .map(|a| a.id.to_string())
+                                .collect::<Vec<_>>()
+                                .join(",");
+                            if !ids_str.is_empty() {
+                                add_action.dispatch(AddHostApplications {
+                                    host_id,
+                                    application_ids: ids_str,
+                                });
+                            }
+                        }
+                    >
+                        "Add selected"
+                    </button>
+                </div>
+            </div>
+        </div>
+    }.into_any()
+}
+
+// ─── Delete confirmation modal ────────────────────────────────────────────────
+
+#[component]
+fn DeleteModal(
+    host_name: String,
+    delete_action: ServerAction<DeleteHost>,
+    host_id: i64,
+    show_modal: RwSignal<bool>,
+) -> impl IntoView {
+    view! {
+        <div class="modal-backdrop" on:click=move |_| show_modal.set(false)>
+            <div class="modal" on:click=move |e| e.stop_propagation()>
+                <div class="modal__header">
+                    <h2>"Delete host"</h2>
+                    <button class="modal__close" type="button" aria-label="Close"
+                        on:click=move |_| show_modal.set(false)>
+                        "×"
+                    </button>
+                </div>
+                <div class="modal__body">
+                    <p class="warning">
+                        "Are you sure you want to delete "
+                        <strong>{host_name}</strong>
+                        "? All port and application associations will also be removed."
+                    </p>
+                </div>
+                <div class="modal__actions">
+                    <button class="btn-secondary" type="button"
+                        on:click=move |_| show_modal.set(false)>
+                        "Cancel"
+                    </button>
+                    <button class="btn-danger" type="button"
+                        on:click=move |_| { delete_action.dispatch(DeleteHost { id: host_id }); }>
+                        "Delete"
+                    </button>
+                </div>
+            </div>
+        </div>
+    }.into_any()
+}
+
+// ─── Main page component ──────────────────────────────────────────────────────
+
+#[component]
+pub fn HostDetailPage() -> impl IntoView {
+    let params = use_params_map();
+    let host_id = move || {
+        params.read().get("id")
+            .and_then(|s| s.parse::<i64>().ok())
+            .unwrap_or(0)
+    };
+
+    let query = use_query_map();
+    let back_url = move || {
+        query.read().get("back")
+            .map(|s| s.to_string())
+            .unwrap_or_else(|| "/hosts".to_string())
+    };
+    let back_label = move || {
+        if back_url().starts_with("/networks/")     { "← Network" }
+        else if back_url().starts_with("/applications/") { "← Application" }
+        else { "← Hosts" }
+    };
+
+    let update_action      = ServerAction::<UpdateHost>::new();
+    let add_port_action    = ServerAction::<AddHostPort>::new();
+    let remove_port_action = ServerAction::<RemoveHostPort>::new();
+    let add_app_action     = ServerAction::<AddHostApplications>::new();
+    let remove_app_action  = ServerAction::<RemoveHostApplication>::new();
+    let delete_action      = ServerAction::<DeleteHost>::new();
+
+    let show_delete_modal  = RwSignal::new(false);
+    let show_add_app_modal = RwSignal::new(false);
+
+    // Auto-close the add-app modal when the action completes successfully.
+    // Lives here (not inside AddAppModal) so it is never recreated across modal open/close cycles.
+    Effect::new(move |was_pending: Option<bool>| {
+        let is_pending = add_app_action.pending().get();
+        if was_pending == Some(true) && !is_pending {
+            if let Some(Ok(_)) = add_app_action.value().get() {
+                show_add_app_modal.set(false);
+            }
+        }
+        is_pending
+    });
+
+    // LocalResource avoids reading the resource outside <Suspense> during hydration,
+    // which would cause a mismatch between the SSR-rendered fallback and the content
+    // the WASM expects to find after the resource resolves.
+    let host = LocalResource::new(move || {
+        let _ = update_action.version().get();
+        let _ = add_port_action.version().get();
+        let _ = remove_port_action.version().get();
+        let _ = add_app_action.version().get();
+        let _ = remove_app_action.version().get();
+        get_host_detail(host_id())
+    });
+
+    // Networks dropdown — LocalResource avoids SSR/hydration mismatch.
+    let networks_res = LocalResource::new(|| get_networks());
+
+    // Available apps for the modal: re-fetched whenever add/remove completes.
+    let add_app_ver    = add_app_action.version();
+    let remove_app_ver = remove_app_action.version();
+    let available_apps_res = LocalResource::new(move || {
+        let _ = add_app_ver.get();
+        let _ = remove_app_ver.get();
+        get_applications_not_on_host(host_id())
+    });
+
+    let name_sig   = RwSignal::new(String::new());
+    let ip_sig     = RwSignal::new(String::new());
+    let net_id_sig = RwSignal::new(0i64);
+    let new_port   = RwSignal::new(String::new());
+
+    // Sync edit signals whenever fresh host data arrives.
+    // LocalResource wraps its value in SendWrapper, so we dereference with `*r`.
+    Effect::new(move |_| {
+        if let Some(r) = host.get() {
+            if let Ok(ref detail) = *r {
+                name_sig.set(detail.name.clone());
+                ip_sig.set(detail.ip.clone());
+                net_id_sig.set(detail.network_id);
+            }
+        }
+    });
+
+    let navigate = use_navigate();
+    Effect::new(move |_| {
+        if let Some(Ok(true)) = delete_action.value().get() {
+            navigate("/hosts", Default::default());
+        }
+    });
+
+    view! {
+        <div class="host-detail-page">
+            // Modals live OUTSIDE <Suspense> so they are not unmounted when the
+            // host resource re-fetches (which would kill their reactive subscriptions).
+            {move || show_add_app_modal.get().then(|| view! {
+                <AddAppModal
+                    host_id=host_id()
+                    available_apps_res=available_apps_res
+                    add_action=add_app_action
+                    show_modal=show_add_app_modal
+                />
+            })}
+            {move || show_delete_modal.get().then(|| view! {
+                <DeleteModal
+                    host_name=name_sig.get()
+                    delete_action=delete_action
+                    host_id=host_id()
+                    show_modal=show_delete_modal
+                />
+            })}
+
+            <Suspense fallback=|| view! { <p class="empty">"Loading host…"</p> }>
+                {move || host.get().map(|r| match (*r).clone() {
+                    Err(e) => view! {
+                        <p class="error">"Could not load host: " {e.to_string()}</p>
+                    }.into_any(),
+
+                    Ok(detail) => {
+                        let id           = detail.id;
+                        let port_count   = detail.ports.len();
+                        let app_count    = detail.applications.len();
+                        let ports        = detail.ports;
+                        let applications = detail.applications;
+
+                        // Pre-built ports view — consumes `ports` once, not reactively.
+                        let ports_list = if ports.is_empty() {
+                            view! {
+                                <p class="empty">"No ports open on this host."</p>
+                            }.into_any()
+                        } else {
+                            view! {
+                                <div class="port-list">
+                                    {ports.into_iter().map(|port| {
+                                        let num = port.number;
+                                        view! {
+                                            <div class="port-row">
+                                                <span class="port-row__number">{num}</span>
+                                                <span class="port-row__desc">
+                                                    {port.description.unwrap_or_default()}
+                                                </span>
+                                                <button
+                                                    class="btn-danger"
+                                                    type="button"
+                                                    on:click=move |_| {
+                                                        remove_port_action.dispatch(
+                                                            RemoveHostPort { host_id: id, port_number: num as i64 }
+                                                        );
+                                                    }
+                                                >
+                                                    "Remove"
+                                                </button>
+                                            </div>
+                                        }
+                                    }).collect_view()}
+                                </div>
+                            }.into_any()
+                        };
+
+                        // Pre-built applications view.
+                        let apps_list = if applications.is_empty() {
+                            view! {
+                                <p class="empty">"No applications linked to this host."</p>
+                            }.into_any()
+                        } else {
+                            view! {
+                                <div class="app-list">
+                                    {applications.into_iter().map(|app| {
+                                        let app_id = app.id;
+                                        view! {
+                                            <div class="app-row">
+                                                <a class="table-link app-row__name"
+                                                    href=format!("/applications/{}?back=/hosts/{}", app_id, id)>
+                                                    {app.name}
+                                                </a>
+                                                <button
+                                                    class="btn-danger"
+                                                    type="button"
+                                                    on:click=move |_| {
+                                                        remove_app_action.dispatch(
+                                                            RemoveHostApplication { host_id: id, application_id: app_id }
+                                                        );
+                                                    }
+                                                >
+                                                    "Remove"
+                                                </button>
+                                            </div>
+                                        }
+                                    }).collect_view()}
+                                </div>
+                            }.into_any()
+                        };
+
+                        view! {
+                            // ── Page header ──────────────────────────────────
+                            <div class="page-header detail-page-header">
+                                <a class="back-btn" href=move || back_url()>
+                                    {move || back_label()}
+                                </a>
+                                <h1 class="detail-page-title">{move || name_sig.get()}</h1>
+                            </div>
+
+                            // ── Identity form ─────────────────────────────────
+                            <section class="detail-section">
+                                <h2 class="detail-section__title">"Identity"</h2>
+                                <div class="detail-form">
+                                    <label class="detail-field">
+                                        "Name"
+                                        <input
+                                            type="text"
+                                            prop:value=move || name_sig.get()
+                                            on:input=move |e| name_sig.set(event_target_value(&e))
+                                        />
+                                    </label>
+                                    <label class="detail-field">
+                                        "IP address"
+                                        <input
+                                            type="text"
+                                            prop:value=move || ip_sig.get()
+                                            on:input=move |e| ip_sig.set(event_target_value(&e))
+                                        />
+                                    </label>
+                                    <label class="detail-field">
+                                        "Network"
+                                        <select on:change=move |e| {
+                                            net_id_sig.set(
+                                                event_target_value(&e).parse().unwrap_or(0)
+                                            );
+                                        }>
+                                            {move || networks_res.get()
+                                                .and_then(|r| (*r).clone().ok())
+                                                .map(|nets| {
+                                                    let current = net_id_sig.get();
+                                                    nets.into_iter().map(|n| {
+                                                        let label = format!("{} - {}", n.name, n.cidr);
+                                                        view! {
+                                                            <option
+                                                                value=n.id.to_string()
+                                                                selected=n.id == current
+                                                            >
+                                                                {label}
+                                                            </option>
+                                                        }
+                                                    }).collect_view()
+                                                })
+                                            }
+                                        </select>
+                                    </label>
+
+                                    {move || update_action.value().get()
+                                        .and_then(|r| r.err())
+                                        .map(|e| view! { <p class="error">{e.to_string()}</p> })
+                                    }
+
+                                    <div class="form-actions">
+                                        <button
+                                            class="btn-primary"
+                                            type="button"
+                                            on:click=move |_| {
+                                                update_action.dispatch(UpdateHost {
+                                                    id,
+                                                    name:       name_sig.get_untracked(),
+                                                    ip:         ip_sig.get_untracked(),
+                                                    network_id: net_id_sig.get_untracked(),
+                                                });
+                                            }
+                                        >
+                                            "Save changes"
+                                        </button>
+                                    </div>
+                                </div>
+                            </section>
+
+                            // ── Ports section ─────────────────────────────────
+                            <section class="detail-section">
+                                <h2 class="detail-section__title">
+                                    {format!("Open ports ({})", port_count)}
+                                </h2>
+
+                                {ports_list}
+
+                                {move || remove_port_action.value().get()
+                                    .and_then(|r| r.err())
+                                    .map(|e| view! {
+                                        <p class="error">"Remove failed: " {e.to_string()}</p>
+                                    })
+                                }
+
+                                <div class="port-add-row">
+                                    <input
+                                        type="number"
+                                        min="1"
+                                        max="65535"
+                                        placeholder="Port number (1–65535)"
+                                        prop:value=move || new_port.get()
+                                        on:input=move |e| new_port.set(event_target_value(&e))
+                                    />
+                                    <button
+                                        class="btn-primary"
+                                        type="button"
+                                        on:click=move |_| {
+                                            let raw = new_port.get_untracked();
+                                            if let Ok(n) = raw.trim().parse::<i64>() {
+                                                if (1..=65535).contains(&n) {
+                                                    add_port_action.dispatch(AddHostPort {
+                                                        host_id: id,
+                                                        port_number: n,
+                                                    });
+                                                    new_port.set(String::new());
+                                                }
+                                            }
+                                        }
+                                    >
+                                        "Add port"
+                                    </button>
+                                    {move || add_port_action.value().get()
+                                        .and_then(|r| r.err())
+                                        .map(|e| view! {
+                                            <p class="error">"Add failed: " {e.to_string()}</p>
+                                        })
+                                    }
+                                </div>
+                            </section>
+
+                            // ── Applications section ──────────────────────────
+                            <section class="detail-section">
+                                <h2 class="detail-section__title">
+                                    {format!("Applications ({})", app_count)}
+                                </h2>
+
+                                {apps_list}
+
+                                {move || remove_app_action.value().get()
+                                    .and_then(|r| r.err())
+                                    .map(|e| view! {
+                                        <p class="error">"Remove failed: " {e.to_string()}</p>
+                                    })
+                                }
+
+                                <div class="port-add-row">
+                                    <button
+                                        class="btn-primary"
+                                        type="button"
+                                        on:click=move |_| show_add_app_modal.set(true)
+                                    >
+                                        "+ Add applications"
+                                    </button>
+                                </div>
+                            </section>
+
+                            // ── Danger zone ───────────────────────────────────
+                            <div class="danger-zone">
+                                <button
+                                    class="btn-danger-solid"
+                                    type="button"
+                                    on:click=move |_| show_delete_modal.set(true)
+                                >
+                                    "Delete host"
+                                </button>
+                            </div>
+                        }.into_any()
+                    }
+                })}
+            </Suspense>
+        </div>
+    }.into_any()
+}

src/client/hosts.rs

@@ -2,7 +2,7 @@
 //
 // Displays all hosts across every network with:
 //   - Add button   : opens a modal form to create a host inside a chosen network
-//   - Filter bar   : name (substring), network, open port, application
+//   - Filter bar   : name (substring), network, open ports (CSV), application
 //   - Table        : name, IP, network, port count, application count, delete
 //   - Pagination   : configurable page size (15 / 25 / 50 / 100 / All)
 //
@@ -12,6 +12,7 @@
 
 use leptos::prelude::*;
 use leptos::form::ActionForm;
+use leptos::html::Input;
 
 use crate::api::{
     applications::get_applications,
@@ -27,25 +28,69 @@ const PER_PAGE_OPTIONS: &[(i64, &str)] = &[
     (0,   "All"),
 ];
 
+// ─── Delete host modal ────────────────────────────────────────────────────────
+
+#[component]
+fn DeleteHostModal(
+    host_name: String,
+    host_id: i64,
+    delete_action: ServerAction<DeleteHost>,
+    pending_delete: RwSignal<Option<(i64, String)>>,
+) -> impl IntoView {
+    view! {
+        <div class="modal-backdrop" on:click=move |_| pending_delete.set(None)>
+            <div class="modal" on:click=move |e| e.stop_propagation()>
+                <div class="modal__header">
+                    <h2>"Delete host"</h2>
+                    <button class="modal__close" type="button" aria-label="Close"
+                        on:click=move |_| pending_delete.set(None)>
+                        "×"
+                    </button>
+                </div>
+                <div class="modal__body">
+                    <p class="warning">
+                        "Are you sure you want to delete "
+                        <strong>{host_name}</strong>
+                        "? All port associations will also be removed."
+                    </p>
+                </div>
+                <div class="modal__actions">
+                    <button class="btn-secondary" type="button"
+                        on:click=move |_| pending_delete.set(None)>
+                        "Cancel"
+                    </button>
+                    <button class="btn-danger" type="button"
+                        on:click=move |_| { delete_action.dispatch(DeleteHost { id: host_id }); }>
+                        "Delete"
+                    </button>
+                </div>
+            </div>
+        </div>
+    }.into_any()
+}
+
 // ─── Add host modal ───────────────────────────────────────────────────────────
 
 #[component]
 fn AddHostModal(
     create_action: ServerAction<CreateHost>,
-    networks_res: Resource<Result<Vec<crate::models::Network>, ServerFnError>>,
+    networks_res: LocalResource<Result<Vec<crate::models::Network>, ServerFnError>>,
     show_modal: RwSignal<bool>,
 ) -> impl IntoView {
-    // Close the modal automatically after a successful creation.
-    Effect::new(move |_| {
-        if let Some(Ok(_)) = create_action.value().get() {
-            show_modal.set(false);
+    use leptos::task::spawn_local;
+
+    let name_ref = NodeRef::<Input>::new();
+
+    spawn_local(async move {
+        if let Some(el) = name_ref.get_untracked() {
+            let _ = el.focus();
         }
     });
 
+    let close = move || spawn_local(async move { show_modal.set(false) });
+
     view! {
-        // Backdrop — click outside the card to close
-        <div class="modal-backdrop" on:click=move |_| show_modal.set(false)>
-            // stop_propagation keeps clicks inside the card from closing the modal
+        <div class="modal-backdrop" on:click=move |_| close()>
             <div class="modal" on:click=move |e| e.stop_propagation()>
                 <div class="modal__header">
                     <h2>"Add a host"</h2>
@@ -53,7 +98,7 @@ fn AddHostModal(
                         class="modal__close"
                         type="button"
                         aria-label="Close"
-                        on:click=move |_| show_modal.set(false)
+                        on:click=move |_| close()
                     >"×"</button>
                 </div>
 
@@ -61,7 +106,7 @@ fn AddHostModal(
                     <div class="add-form__fields">
                         <label>
                             "Name"
-                            <input type="text" name="name" placeholder="e.g. web-server-01" required/>
+                            <input node_ref=name_ref type="text" name="name" placeholder="e.g. web-server-01" required/>
                         </label>
                         <label>
                             "IP address"
@@ -72,20 +117,30 @@ fn AddHostModal(
                             <select name="network_id" required>
                                 <option value="">"— choose —"</option>
                                 {move || networks_res.get()
-                                    .and_then(|r| r.ok())
+                                    .and_then(|r| (*r).clone().ok())
                                     .map(|nets| nets.into_iter().map(|n| {
-                                        view! { <option value=n.id.to_string()>{n.name}</option> }
+                                        let label = format!("{} - {}", n.name, n.cidr);
+                                        view! { <option value=n.id.to_string()>{label}</option> }
                                     }).collect_view())
                                 }
                             </select>
                         </label>
+                        <label>
+                            "Open ports"
+                            <input
+                                type="text"
+                                name="ports"
+                                placeholder="e.g. 22, 80, 443"
+                            />
+                            <span class="field-hint">"Comma-separated port numbers"</span>
+                        </label>
                     </div>
 
                     <div class="modal__actions">
                         <button
                             class="btn-secondary"
                             type="button"
-                            on:click=move |_| show_modal.set(false)
+                            on:click=move |_| close()
                         >"Cancel"</button>
                         <button type="submit">"Add host"</button>
                     </div>
@@ -104,11 +159,11 @@ fn AddHostModal(
 
 #[component]
 fn FilterBar(
-    networks_res: Resource<Result<Vec<crate::models::Network>, ServerFnError>>,
-    applications_res: Resource<Result<Vec<crate::models::Application>, ServerFnError>>,
+    networks_res: LocalResource<Result<Vec<crate::models::Network>, ServerFnError>>,
+    applications_res: LocalResource<Result<Vec<crate::models::Application>, ServerFnError>>,
     name_filter: RwSignal<String>,
     network_id_filter: RwSignal<i64>,
-    port_filter: RwSignal<i64>,
+    port_filter: RwSignal<String>,
     app_id_filter: RwSignal<i64>,
     page: RwSignal<i64>,
 ) -> impl IntoView {
@@ -135,23 +190,22 @@ fn FilterBar(
                     }>
                         <option value="0">"All networks"</option>
                         {move || networks_res.get()
-                            .and_then(|r| r.ok())
+                            .and_then(|r| (*r).clone().ok())
                             .map(|nets| nets.into_iter().map(|n| {
-                                view! { <option value=n.id.to_string()>{n.name}</option> }
+                                let label = format!("{} - {}", n.name, n.cidr);
+                                view! { <option value=n.id.to_string()>{label}</option> }
                             }).collect_view())
                         }
                     </select>
                 </label>
 
                 <label class="filter-field">
-                    "Open port"
+                    "Open ports"
                     <input
-                        type="number"
-                        min="1"
-                        max="65535"
-                        placeholder="e.g. 443"
+                        type="text"
+                        placeholder="e.g. 80, 443 (all required)"
                         on:change=move |e| {
-                            port_filter.set(event_target_value(&e).parse().unwrap_or(0));
+                            port_filter.set(event_target_value(&e));
                             page.set(1);
                         }
                     />
@@ -165,7 +219,7 @@ fn FilterBar(
                     }>
                         <option value="0">"All applications"</option>
                         {move || applications_res.get()
-                            .and_then(|r| r.ok())
+                            .and_then(|r| (*r).clone().ok())
                             .map(|apps| apps.into_iter().map(|a| {
                                 view! { <option value=a.id.to_string()>{a.name}</option> }
                             }).collect_view())
@@ -212,7 +266,6 @@ fn PaginationBar(
                     </select>
                 </label>
 
-                // Page navigation — hidden when showing all results (per_page == 0)
                 {move || (per_page.get() > 0).then(|| view! {
                     <div class="pagination-nav">
                         <button
@@ -240,12 +293,12 @@ fn PaginationBar(
 
 #[component]
 fn HostTable(
-    hosts: Resource<Result<HostsPageData, ServerFnError>>,
-    delete_action: ServerAction<DeleteHost>,
+    hosts: LocalResource<Result<HostsPageData, ServerFnError>>,
+    pending_delete: RwSignal<Option<(i64, String)>>,
 ) -> impl IntoView {
     view! {
         <Suspense fallback=|| view! { <p class="empty">"Loading hosts…"</p> }>
-            {move || hosts.get().map(|result| match result {
+            {move || hosts.get().map(|r| match (*r).clone() {
                 Err(e) => view! {
                     <p class="error">"Could not load hosts: " {e.to_string()}</p>
                 }.into_any(),
@@ -270,6 +323,7 @@ fn HostTable(
                             <tbody>
                                 {rows.into_iter().map(|host| {
                                     let id = host.id;
+                                    let delete_name = host.name.clone();
                                     view! {
                                         <tr>
                                             <td>
@@ -287,7 +341,7 @@ fn HostTable(
                                             <td class="col-count">{host.application_count}</td>
                                             <td class="col-actions">
                                                 <button on:click=move |_| {
-                                                    delete_action.dispatch(DeleteHost { id });
+                                                    pending_delete.set(Some((id, delete_name.clone())));
                                                 }>
                                                     "Delete"
                                                 </button>
@@ -308,48 +362,65 @@ fn HostTable(
 
 #[component]
 pub fn HostsPage() -> impl IntoView {
-    // Actions
     let create_action = ServerAction::<CreateHost>::new();
     let delete_action = ServerAction::<DeleteHost>::new();
 
-    // Controls the add-host modal
     let show_modal = RwSignal::new(false);
 
-    // Filter signals (0 / "" = no filter)
+    // None = no modal, Some((id, name)) = delete confirmation open.
+    let pending_delete: RwSignal<Option<(i64, String)>> = RwSignal::new(None);
+
+    // Close the add modal on pending→done with Ok (lives in parent to avoid stale-value re-trigger).
+    Effect::new(move |was_pending: Option<bool>| {
+        let is_pending = create_action.pending().get();
+        if was_pending == Some(true) && !is_pending {
+            if let Some(Ok(_)) = create_action.value().get() {
+                show_modal.set(false);
+            }
+        }
+        is_pending
+    });
+
+    // Close the delete modal automatically after a successful deletion.
+    Effect::new(move |_| {
+        if let Some(Ok(_)) = delete_action.value().get() {
+            pending_delete.set(None);
+        }
+    });
+
+    // Filter signals ("" / 0 = no filter)
     let name_filter       = RwSignal::new(String::new());
     let network_id_filter = RwSignal::new(0i64);
-    let port_filter       = RwSignal::new(0i64);
+    let port_filter       = RwSignal::new(String::new()); // CSV of port numbers
     let app_id_filter     = RwSignal::new(0i64);
 
-    // Pagination signals
     let page     = RwSignal::new(1i64);
     let per_page = RwSignal::new(15i64);
 
-    // Hosts resource — refetches whenever any filter/pagination/action changes
-    let hosts = Resource::new(
-        move || (
+    // LocalResource avoids reading a resource outside <Suspense> during hydration.
+    // All dependencies (filters, pagination, action versions) are client-side only,
+    // so there is no benefit to SSR for this resource.
+    let hosts = LocalResource::new(move || {
+        let _ = create_action.version().get();
+        let _ = delete_action.version().get();
+        get_hosts_page(
             name_filter.get(),
             network_id_filter.get(),
             port_filter.get(),
             app_id_filter.get(),
             page.get(),
             per_page.get(),
-            create_action.version().get(),
-            delete_action.version().get(),
-        ),
-        |(name, net, port, app, p, pp, _, _)| get_hosts_page(name, net, port, app, p, pp),
-    );
+        )
+    });
 
-    // Dropdown resources (fetched once on mount)
-    let networks_res     = Resource::new(|| (), |_| get_networks());
-    let applications_res = Resource::new(|| (), |_| get_applications());
+    let networks_res     = LocalResource::new(|| get_networks());
+    let applications_res = LocalResource::new(|| get_applications());
 
-    // Derived pagination signals
     let total_pages = Signal::derive(move || {
-        hosts.get().and_then(|r| r.ok()).map(|p| p.total_pages).unwrap_or(1)
+        hosts.get().and_then(|r| (*r).clone().ok()).map(|p| p.total_pages).unwrap_or(1)
     });
     let total = Signal::derive(move || {
-        hosts.get().and_then(|r| r.ok()).map(|p| p.total).unwrap_or(0)
+        hosts.get().and_then(|r| (*r).clone().ok()).map(|p| p.total).unwrap_or(0)
     });
 
     view! {
@@ -361,7 +432,6 @@ pub fn HostsPage() -> impl IntoView {
                 </button>
             </div>
 
-            // Modal — only rendered when show_modal is true
             {move || show_modal.get().then(|| view! {
                 <AddHostModal
                     create_action=create_action
@@ -370,6 +440,15 @@ pub fn HostsPage() -> impl IntoView {
                 />
             })}
 
+            {move || pending_delete.get().map(|(host_id, host_name)| view! {
+                <DeleteHostModal
+                    host_name=host_name
+                    host_id=host_id
+                    delete_action=delete_action
+                    pending_delete=pending_delete
+                />
+            })}
+
             <FilterBar
                 networks_res=networks_res
                 applications_res=applications_res
@@ -388,7 +467,7 @@ pub fn HostsPage() -> impl IntoView {
 
                 <PaginationBar total=total page=page per_page=per_page total_pages=total_pages/>
 
-                <HostTable hosts=hosts delete_action=delete_action/>
+                <HostTable hosts=hosts pending_delete=pending_delete/>
             </section>
         </div>
     }.into_any()

src/client/mod.rs

@@ -9,7 +9,11 @@
 // Do not place code here that requires browser-only APIs (window, document...)
 // without guarding it with `#[cfg(target_arch = "wasm32")]`.
 
-pub mod home;     // Home page
-pub mod hosts;    // Hosts list with filters and pagination
-pub mod networks; // Networks list and creation
-pub mod theme;    // Theme toggle component (light / dark / system)
+pub mod application_detail; // Application detail: identity, ports, linked hosts, delete
+pub mod applications;       // Applications list and creation
+pub mod home;               // Home page
+pub mod host_detail;        // Host detail: identity, ports, edit, delete
+pub mod hosts;              // Hosts list with filters and pagination
+pub mod network_detail;     // Network detail: info + paginated host list
+pub mod networks;           // Networks list and creation
+pub mod theme;              // Theme toggle component (light / dark / system)

src/client/network_detail.rs

@@ -0,0 +1,200 @@
+// client/network_detail.rs — Network detail page
+//
+// Displays a single network (name + CIDR) with a paginated list of its hosts.
+// Each host name links to /hosts/:id?back=/networks/:network_id so that the
+// host detail page can offer a contextual "back to network" button.
+
+use leptos::prelude::*;
+use leptos_router::hooks::use_params_map;
+
+use crate::api::{
+    hosts::{get_hosts_page, HostsPage as HostsPageData},
+    networks::get_network,
+};
+
+const PER_PAGE_OPTIONS: &[(i64, &str)] = &[
+    (15,  "15"),
+    (25,  "25"),
+    (50,  "50"),
+    (100, "100"),
+    (0,   "All"),
+];
+
+// ─── Main page component ──────────────────────────────────────────────────────
+
+#[component]
+pub fn NetworkDetailPage() -> impl IntoView {
+    let params = use_params_map();
+    let network_id = move || {
+        params.read().get("id")
+            .and_then(|s| s.parse::<i64>().ok())
+            .unwrap_or(0)
+    };
+
+    let page     = RwSignal::new(1i64);
+    let per_page = RwSignal::new(15i64);
+
+    // Network metadata — reloads only when the ID changes.
+    let network = Resource::new(
+        move || network_id(),
+        |id| get_network(id),
+    );
+
+    // Paginated host list for this network.
+    // Guards against network_id = 0 to avoid fetching all hosts.
+    let hosts = Resource::new(
+        move || (network_id(), page.get(), per_page.get()),
+        |(net_id, p, pp)| async move {
+            if net_id == 0 {
+                return Err(ServerFnError::new("Invalid network ID"));
+            }
+            get_hosts_page(String::new(), net_id, String::new(), 0, p, pp).await
+        },
+    );
+
+    let total_pages = Signal::derive(move || {
+        hosts.get().and_then(|r| r.ok()).map(|d| d.total_pages).unwrap_or(1)
+    });
+    let total = Signal::derive(move || {
+        hosts.get().and_then(|r| r.ok()).map(|d| d.total).unwrap_or(0)
+    });
+
+    view! {
+        <div class="network-detail-page">
+            <Suspense fallback=|| view! { <p class="empty">"Loading network…"</p> }>
+                {move || network.get().map(|result| match result {
+                    Err(e) => view! {
+                        <p class="error">"Could not load network: " {e.to_string()}</p>
+                    }.into_any(),
+
+                    Ok(net) => {
+                        let net_id = net.id;
+                        view! {
+                            // ── Header ────────────────────────────────────────
+                            <div class="page-header detail-page-header">
+                                <a class="back-btn" href="/networks">"← Networks"</a>
+                                <h1 class="detail-page-title">{net.name}</h1>
+                                <p class="network-detail-cidr">{net.cidr}</p>
+                            </div>
+
+                            // ── Hosts section ────────────────────────────────
+                            <section class="detail-section">
+                                <h2 class="detail-section__title">"Hosts"</h2>
+
+                                // Pagination bar
+                                <div class="pagination-bar">
+                                    <div class="pagination-bar__info">
+                                        {move || {
+                                            let t = total.get();
+                                            if t == 0 { "No hosts".to_string() }
+                                            else { format!("{} host{}", t, if t == 1 { "" } else { "s" }) }
+                                        }}
+                                    </div>
+                                    <div class="pagination-bar__controls">
+                                        <label class="pagination-per-page">
+                                            "Per page "
+                                            <select on:change=move |e| {
+                                                per_page.set(
+                                                    event_target_value(&e).parse().unwrap_or(15)
+                                                );
+                                                page.set(1);
+                                            }>
+                                                {PER_PAGE_OPTIONS.iter().map(|(v, label)| {
+                                                    view! {
+                                                        <option value=v.to_string() selected=*v == 15>
+                                                            {*label}
+                                                        </option>
+                                                    }
+                                                }).collect_view()}
+                                            </select>
+                                        </label>
+                                        {move || (per_page.get() > 0).then(|| view! {
+                                            <div class="pagination-nav">
+                                                <button
+                                                    disabled=move || page.get() <= 1
+                                                    on:click=move |_| page.update(|p| *p = (*p - 1).max(1))
+                                                >"‹"</button>
+                                                <span class="pagination-nav__label">
+                                                    {move || format!(
+                                                        "Page {} of {}",
+                                                        page.get(),
+                                                        total_pages.get().max(1)
+                                                    )}
+                                                </span>
+                                                <button
+                                                    disabled={move || page.get() >= total_pages.get()}
+                                                    on:click=move |_| {
+                                                        let max = total_pages.get_untracked();
+                                                        page.update(|p| *p = (*p + 1).min(max));
+                                                    }
+                                                >"›"</button>
+                                            </div>
+                                        })}
+                                    </div>
+                                </div>
+
+                                // Host table
+                                <Suspense fallback=|| view! {
+                                    <p class="empty">"Loading hosts…"</p>
+                                }>
+                                    {move || hosts.get().map(|result| match result {
+                                        Err(e) => view! {
+                                            <p class="error">
+                                                "Could not load hosts: " {e.to_string()}
+                                            </p>
+                                        }.into_any(),
+
+                                        Ok(HostsPageData { rows, .. }) if rows.is_empty() => view! {
+                                            <p class="empty">"No hosts in this network."</p>
+                                        }.into_any(),
+
+                                        Ok(HostsPageData { rows, .. }) => view! {
+                                            <div class="table-container">
+                                                <table>
+                                                    <thead>
+                                                        <tr>
+                                                            <th>"Name"</th>
+                                                            <th>"IP"</th>
+                                                            <th class="col-count">"Ports"</th>
+                                                            <th class="col-count">"Apps"</th>
+                                                        </tr>
+                                                    </thead>
+                                                    <tbody>
+                                                        {rows.into_iter().map(|host| {
+                                                            // Pass the current network as the back destination
+                                                            // so the host detail page can link back here.
+                                                            let href = format!(
+                                                                "/hosts/{}?back=/networks/{}",
+                                                                host.id, net_id
+                                                            );
+                                                            view! {
+                                                                <tr>
+                                                                    <td>
+                                                                        <a class="table-link" href=href>
+                                                                            {host.name}
+                                                                        </a>
+                                                                    </td>
+                                                                    <td class="cell-mono">{host.ip}</td>
+                                                                    <td class="col-count">
+                                                                        {host.port_count}
+                                                                    </td>
+                                                                    <td class="col-count">
+                                                                        {host.application_count}
+                                                                    </td>
+                                                                </tr>
+                                                            }
+                                                        }).collect_view()}
+                                                    </tbody>
+                                                </table>
+                                            </div>
+                                        }.into_any(),
+                                    })}
+                                </Suspense>
+                            </section>
+                        }.into_any()
+                    }
+                })}
+            </Suspense>
+        </div>
+    }.into_any()
+}

src/client/networks.rs

@@ -166,9 +166,15 @@ pub fn NetworksPage() -> impl IntoView {
                                                 .into_iter()
                                                 .map(|network| {
                                                     let network_clone = network.clone();
+                                                    let net_id = network.id;
                                                     view! {
                                                         <tr>
-                                                            <td>{network.name}</td>
+                                                            <td>
+                                                                <a class="table-link"
+                                                                    href=format!("/networks/{}", net_id)>
+                                                                    {network.name}
+                                                                </a>
+                                                            </td>
                                                             <td class="cell-mono">{network.cidr}</td>
                                                             <td class="col-count">{network.host_count}</td>
                                                             <td class="col-count">{network.application_count}</td>

src/server/repository/applications.rs

@@ -42,6 +42,18 @@ pub async fn create_application(pool: &AnyPool, name: &str) -> Result<Applicatio
     Ok(row_to_application(&row))
 }
 
+/// Updates the name of an application. Returns the updated record.
+pub async fn update_application(pool: &AnyPool, id: i64, name: &str) -> Result<Application, DbError> {
+    let row = sqlx::query(
+        "UPDATE applications SET name = $1 WHERE id = $2 RETURNING id, name",
+    )
+    .bind(name)
+    .bind(id)
+    .fetch_one(pool)
+    .await?;
+    Ok(row_to_application(&row))
+}
+
 /// Deletes an application and its port associations (via `ON DELETE CASCADE`).
 ///
 /// Returns `true` if a row was deleted, `false` if the id did not exist.
@@ -54,6 +66,84 @@ pub async fn delete_application(pool: &AnyPool, id: i64) -> Result<bool, DbError
     Ok(result.rows_affected() > 0)
 }
 
+// ─── Host-application associations ───────────────────────────────────────────
+
+/// Returns all applications linked directly to a host, ordered by name.
+pub async fn list_applications_for_host(
+    pool: &AnyPool,
+    host_id: i64,
+) -> Result<Vec<Application>, DbError> {
+    let rows = sqlx::query(
+        "SELECT a.id, a.name
+         FROM applications a
+         JOIN host_applications ha ON ha.application_id = a.id
+         WHERE ha.host_id = $1
+         ORDER BY a.name",
+    )
+    .bind(host_id)
+    .fetch_all(pool)
+    .await?;
+    Ok(rows.iter().map(row_to_application).collect())
+}
+
+/// Returns all applications NOT yet linked to a host, ordered by name.
+pub async fn list_applications_not_on_host(
+    pool: &AnyPool,
+    host_id: i64,
+) -> Result<Vec<Application>, DbError> {
+    let rows = sqlx::query(
+        "SELECT id, name FROM applications
+         WHERE id NOT IN (
+             SELECT application_id FROM host_applications WHERE host_id = $1
+         )
+         ORDER BY name",
+    )
+    .bind(host_id)
+    .fetch_all(pool)
+    .await?;
+    Ok(rows.iter().map(row_to_application).collect())
+}
+
+/// Links an application directly to a host.
+///
+/// If the link already exists, this is a no-op (not an error).
+pub async fn add_application_to_host(
+    pool: &AnyPool,
+    host_id: i64,
+    application_id: i64,
+) -> Result<(), DbError> {
+    let result = sqlx::query(
+        "INSERT INTO host_applications (host_id, application_id) VALUES ($1, $2)",
+    )
+    .bind(host_id)
+    .bind(application_id)
+    .execute(pool)
+    .await;
+    match result {
+        Ok(_) => Ok(()),
+        Err(sqlx::Error::Database(ref e)) if e.is_unique_violation() => Ok(()),
+        Err(e) => Err(DbError::Connection(e)),
+    }
+}
+
+/// Removes the direct link between a host and an application.
+///
+/// Returns `true` if the association existed and was removed.
+pub async fn remove_application_from_host(
+    pool: &AnyPool,
+    host_id: i64,
+    application_id: i64,
+) -> Result<bool, DbError> {
+    let result = sqlx::query(
+        "DELETE FROM host_applications WHERE host_id = $1 AND application_id = $2",
+    )
+    .bind(host_id)
+    .bind(application_id)
+    .execute(pool)
+    .await?;
+    Ok(result.rows_affected() > 0)
+}
+
 // ─── Application-port associations ───────────────────────────────────────────
 
 /// Returns all port numbers associated with an application, sorted numerically.

src/server/repository/hosts.rs

@@ -62,6 +62,33 @@ pub async fn create_host(
     Ok(row_to_host(&row))
 }
 
+/// Updates a host's name, IP address, and network assignment.
+///
+/// Returns the updated host, or `None` if the id does not exist.
+/// The caller must validate that `ip` falls within the CIDR range of the
+/// new `network_id` before calling this function.
+pub async fn update_host(
+    pool: &AnyPool,
+    id: i64,
+    name: &str,
+    ip: &str,
+    network_id: i64,
+) -> Result<Option<Host>, DbError> {
+    let row = sqlx::query(
+        "UPDATE hosts SET name = $1, ip = $2, network_id = $3
+         WHERE id = $4
+         RETURNING id, name, ip, network_id",
+    )
+    .bind(name)
+    .bind(ip)
+    .bind(network_id)
+    .bind(id)
+    .fetch_optional(pool)
+    .await?;
+
+    Ok(row.as_ref().map(row_to_host))
+}
+
 /// Deletes a host and all its port associations (via `ON DELETE CASCADE`).
 ///
 /// Returns `true` if a row was deleted, `false` if the id did not exist.

src/server/repository/networks.rs

@@ -23,7 +23,7 @@ pub async fn list_networks(pool: &AnyPool) -> Result<Vec<Network>, DbError> {
 pub async fn find_network(pool: &AnyPool, id: i64) -> Result<Option<Network>, DbError> {
     // `fetch_optional` returns `Ok(None)` when no row matches — unlike
     // `fetch_one`, which returns an error when nothing is found.
-    let row = sqlx::query("SELECT id, cidr FROM networks WHERE id = $1")
+    let row = sqlx::query("SELECT id, name, cidr FROM networks WHERE id = $1")
         .bind(id) // `$1` is replaced with the value of `id` at runtime
         .fetch_optional(pool)
         .await?;

style/rust-ipam.css

@@ -784,6 +784,13 @@ td.col-actions {
   color: var(--text-secondary);
 }
 
+.field-hint {
+  font-size: var(--font-xs, 0.72rem);
+  font-weight: 400;
+  color: var(--text-muted, var(--text-secondary));
+  opacity: 0.75;
+}
+
 /* ============================================================
    PAGINATION BAR
    ============================================================ */
@@ -1014,6 +1021,67 @@ td.col-actions {
   background: var(--accent-hover);
 }
 
+/* Solid danger button — used for prominent destructive actions (page header) */
+.btn-danger-solid {
+  background: var(--danger);
+  color: #fff;
+  border-color: var(--danger);
+  font-size: var(--font-sm);
+  padding: 8px var(--size-md);
+  font-weight: 500;
+}
+
+.btn-danger-solid:hover {
+  filter: brightness(0.9);
+}
+
+/* Left cluster inside page header: back button stacked above title */
+.page-header__left {
+  display: flex;
+  flex-direction: column;
+  align-items: flex-start;
+  gap: var(--size-xs);
+}
+
+/* Detail page header: back button then centred title */
+.detail-page-header {
+  flex-direction: column;
+  align-items: center;
+  gap: var(--size-xs);
+}
+
+/* Self-align the back button to the left while the title stays centred */
+.detail-page-header .back-btn {
+  align-self: flex-start;
+}
+
+.detail-page-title {
+  text-align: center;
+  width: 100%;
+  margin: 0;
+}
+
+.back-btn {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  font-size: var(--font-xs);
+  font-weight: 500;
+  color: var(--text-secondary);
+  background: var(--bg-surface2);
+  border: 1px solid var(--border);
+  border-radius: var(--radius-sm);
+  padding: 3px 10px;
+  text-decoration: none;
+  cursor: pointer;
+  transition: background var(--transition-fast), color var(--transition-fast);
+}
+
+.back-btn:hover {
+  background: var(--bg-hover);
+  color: var(--text);
+}
+
 /* Delete button inside hosts table */
 .hosts-page td button {
   background: transparent;
@@ -1030,3 +1098,250 @@ td.col-actions {
   background: var(--danger-light);
   border-color: var(--danger);
 }
+
+/* ============================================================
+   HOST DETAIL PAGE
+   ============================================================ */
+
+.host-detail-page {
+  max-width: 720px;
+}
+
+/* Card-like section grouping related fields */
+.detail-section {
+  background: var(--bg-surface);
+  border: 1px solid var(--border);
+  border-radius: var(--radius-md);
+  padding: var(--size-lg);
+  margin-bottom: var(--size-lg);
+}
+
+.detail-section__title {
+  font-size: var(--font-base);
+  font-weight: 600;
+  color: var(--text-secondary);
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+  margin: 0 0 var(--size-md);
+}
+
+/* Stack of label + input pairs */
+.detail-form {
+  display: flex;
+  flex-direction: column;
+  gap: var(--size-md);
+}
+
+.detail-field {
+  display: flex;
+  flex-direction: column;
+  gap: var(--size-xs);
+  font-size: var(--font-sm);
+  font-weight: 500;
+  color: var(--text-secondary);
+}
+
+.detail-field input,
+.detail-field select {
+  width: 100%;
+  box-sizing: border-box;
+}
+
+/* Save button aligned to the right */
+.form-actions {
+  display: flex;
+  justify-content: flex-end;
+  padding-top: var(--size-xs);
+}
+
+/* ── Ports list ─────────────────────────────────────────────── */
+
+.port-list {
+  display: flex;
+  flex-direction: column;
+  margin-bottom: var(--size-md);
+  border-top: 1px solid var(--border);
+}
+
+.port-row {
+  display: flex;
+  align-items: center;
+  gap: var(--size-md);
+  padding: var(--size-sm) var(--size-xs);
+  border-bottom: 1px solid var(--border);
+}
+
+.port-row__number {
+  font-family: var(--font-mono);
+  font-size: var(--font-sm);
+  font-weight: 600;
+  min-width: 4ch;
+  color: var(--accent);
+}
+
+.port-row__desc {
+  flex: 1;
+  font-size: var(--font-sm);
+  color: var(--text-secondary);
+}
+
+/* Add port row: input + button side by side */
+.port-add-row {
+  display: flex;
+  align-items: center;
+  gap: var(--size-sm);
+  padding-top: var(--size-sm);
+  border-top: 1px solid var(--border);
+  margin-top: var(--size-sm);
+  flex-wrap: wrap;
+}
+
+.port-add-row input[type="number"] {
+  width: 200px;
+  flex-shrink: 0;
+}
+
+/* Delete button anchored to the bottom-right of the detail page */
+.danger-zone {
+  display: flex;
+  justify-content: flex-end;
+  margin-top: var(--size-lg);
+}
+
+/* ============================================================
+   NETWORK DETAIL PAGE
+   ============================================================ */
+
+.network-detail-page {
+  max-width: 720px;
+}
+
+/* CIDR displayed below the network name in the header */
+.network-detail-cidr {
+  font-family: var(--font-mono);
+  font-size: var(--font-sm);
+  color: var(--text-secondary);
+  margin: 0;
+}
+
+/* ============================================================
+   HOST DETAIL — APPLICATIONS SECTION
+   ============================================================ */
+
+/* List of applications linked to a host (mirrors .port-list) */
+.app-list {
+  display: flex;
+  flex-direction: column;
+  margin-bottom: var(--size-md);
+  border-top: 1px solid var(--border);
+}
+
+.app-row {
+  display: flex;
+  align-items: center;
+  gap: var(--size-md);
+  padding: var(--size-sm) var(--size-xs);
+  border-bottom: 1px solid var(--border);
+}
+
+.app-row__name {
+  flex: 1;
+  font-size: var(--font-sm);
+}
+
+/* ── Pick list (scrollable, click to select) ── */
+.app-pick-list {
+  list-style: none;
+  margin: 0 0 var(--size-sm);
+  padding: 0;
+  max-height: 220px;
+  overflow-y: auto;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+}
+
+.app-pick-item {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: var(--size-sm) var(--size-md);
+  cursor: pointer;
+  font-size: var(--font-sm);
+  border-bottom: 1px solid var(--border);
+  transition: background 0.1s;
+}
+
+.app-pick-item:last-child {
+  border-bottom: none;
+}
+
+.app-pick-item:hover {
+  background: color-mix(in srgb, var(--accent) 10%, transparent);
+  color: var(--accent);
+}
+
+.app-pick-item__add {
+  font-size: 1.1rem;
+  font-weight: 600;
+  color: var(--accent);
+  opacity: 0.7;
+}
+
+.app-pick-item:hover .app-pick-item__add {
+  opacity: 1;
+}
+
+/* ── Selected tags (shown below the pick list) ── */
+.app-selected-section {
+  display: flex;
+  flex-direction: column;
+  gap: var(--size-xs);
+  padding-top: var(--size-sm);
+  border-top: 1px solid var(--border);
+  margin-top: var(--size-xs);
+}
+
+.app-selected-label {
+  font-size: var(--font-xs, 0.75rem);
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+  color: var(--text-secondary);
+}
+
+.app-selected-list {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--size-xs);
+}
+
+.app-selected-tag {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  padding: 2px 8px 2px 10px;
+  border-radius: 999px;
+  background: color-mix(in srgb, var(--accent) 15%, transparent);
+  border: 1px solid color-mix(in srgb, var(--accent) 40%, transparent);
+  color: var(--accent);
+  font-size: var(--font-sm);
+  font-weight: 500;
+}
+
+.app-selected-tag__remove {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  background: none;
+  border: none;
+  padding: 0 2px;
+  cursor: pointer;
+  font-size: 0.9rem;
+  color: var(--accent);
+  opacity: 0.7;
+  line-height: 1;
+}
+
+.app-selected-tag__remove:hover {
+  opacity: 1;
+}