feat(applications): add application detail page

- New page /applications/:id with identity (editable name), associated
  ports (add/remove), linked hosts (read-only via shared ports), and
  delete with confirmation modal
- Add get_application_detail and update_application server functions
- Add ApplicationDetail and HostRef types in api/applications
- Add update_application to the repository layer
- Application names in the list are now clickable links

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

src/api/applications.rs

@@ -5,6 +5,24 @@ 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
@@ -65,6 +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(
@@ -83,6 +147,24 @@ pub async fn get_ports_for_application(
 
 // ─── Mutations ────────────────────────────────────────────────────────────────
 
+/// Updates the name of an application and returns the updated record.
+#[server]
+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"))?;
+
+    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").