feat(dashboard): add client editing with PUT endpoint and edit modal

Add PUT /api/clients/{id} with dynamic UPDATE for name, description,
is_active, and rate_limit_per_minute. Expose description and
rate_limit_per_minute in client list/detail responses. Replace the
frontend editClient stub with a modal that fetches, edits, and saves
client data.

src/dashboard/clients.rs

@@ -17,6 +17,14 @@ pub(super) struct CreateClientRequest {
     pub(super) client_id: Option<String>,
 }
 
+#[derive(Deserialize)]
+pub(super) struct UpdateClientPayload {
+    pub(super) name: Option<String>,
+    pub(super) description: Option<String>,
+    pub(super) is_active: Option<bool>,
+    pub(super) rate_limit_per_minute: Option<i64>,
+}
+
 pub(super) async fn handle_get_clients(State(state): State<DashboardState>) -> Json<ApiResponse<serde_json::Value>> {
     let pool = &state.app_state.db_pool;
 
@@ -25,11 +33,13 @@ pub(super) async fn handle_get_clients(State(state): State<DashboardState>) -> J
         SELECT 
             client_id as id,
             name,
+            description,
             created_at,
             total_requests,
             total_tokens,
             total_cost,
-            is_active
+            is_active,
+            rate_limit_per_minute
         FROM clients
         ORDER BY created_at DESC
         "#,
@@ -45,11 +55,13 @@ pub(super) async fn handle_get_clients(State(state): State<DashboardState>) -> J
                     serde_json::json!({
                         "id": row.get::<String, _>("id"),
                         "name": row.get::<Option<String>, _>("name").unwrap_or_else(|| "Unnamed".to_string()),
+                        "description": row.get::<Option<String>, _>("description"),
                         "created_at": row.get::<chrono::DateTime<chrono::Utc>, _>("created_at"),
                         "requests_count": row.get::<i64, _>("total_requests"),
                         "total_tokens": row.get::<i64, _>("total_tokens"),
                         "total_cost": row.get::<f64, _>("total_cost"),
                         "status": if row.get::<bool, _>("is_active") { "active" } else { "inactive" },
+                        "rate_limit_per_minute": row.get::<Option<i64>, _>("rate_limit_per_minute"),
                     })
                 })
                 .collect();
@@ -110,7 +122,9 @@ pub(super) async fn handle_get_client(
         SELECT 
             c.client_id as id,
             c.name,
+            c.description,
             c.is_active,
+            c.rate_limit_per_minute,
             c.created_at,
             COALESCE(c.total_tokens, 0) as total_tokens,
             COALESCE(c.total_cost, 0.0) as total_cost,
@@ -130,7 +144,9 @@ pub(super) async fn handle_get_client(
         Ok(Some(row)) => Json(ApiResponse::success(serde_json::json!({
             "id": row.get::<String, _>("id"),
             "name": row.get::<Option<String>, _>("name").unwrap_or_else(|| "Unnamed".to_string()),
+            "description": row.get::<Option<String>, _>("description"),
             "is_active": row.get::<bool, _>("is_active"),
+            "rate_limit_per_minute": row.get::<Option<i64>, _>("rate_limit_per_minute"),
             "created_at": row.get::<chrono::DateTime<chrono::Utc>, _>("created_at"),
             "total_tokens": row.get::<i64, _>("total_tokens"),
             "total_cost": row.get::<f64, _>("total_cost"),
@@ -146,6 +162,98 @@ pub(super) async fn handle_get_client(
     }
 }
 
+pub(super) async fn handle_update_client(
+    State(state): State<DashboardState>,
+    Path(id): Path<String>,
+    Json(payload): Json<UpdateClientPayload>,
+) -> Json<ApiResponse<serde_json::Value>> {
+    let pool = &state.app_state.db_pool;
+
+    // Build dynamic UPDATE query from provided fields
+    let mut sets = Vec::new();
+    let mut binds: Vec<String> = Vec::new();
+
+    if let Some(ref name) = payload.name {
+        sets.push("name = ?");
+        binds.push(name.clone());
+    }
+    if let Some(ref desc) = payload.description {
+        sets.push("description = ?");
+        binds.push(desc.clone());
+    }
+    if payload.is_active.is_some() {
+        sets.push("is_active = ?");
+    }
+    if payload.rate_limit_per_minute.is_some() {
+        sets.push("rate_limit_per_minute = ?");
+    }
+
+    if sets.is_empty() {
+        return Json(ApiResponse::error("No fields to update".to_string()));
+    }
+
+    // Always update updated_at
+    sets.push("updated_at = CURRENT_TIMESTAMP");
+
+    let sql = format!("UPDATE clients SET {} WHERE client_id = ?", sets.join(", "));
+    let mut query = sqlx::query(&sql);
+
+    // Bind in the same order as sets
+    for b in &binds {
+        query = query.bind(b);
+    }
+    if let Some(active) = payload.is_active {
+        query = query.bind(active);
+    }
+    if let Some(rate) = payload.rate_limit_per_minute {
+        query = query.bind(rate);
+    }
+    query = query.bind(&id);
+
+    match query.execute(pool).await {
+        Ok(result) => {
+            if result.rows_affected() == 0 {
+                return Json(ApiResponse::error(format!("Client '{}' not found", id)));
+            }
+            // Return the updated client
+            let row = sqlx::query(
+                r#"
+                SELECT client_id as id, name, description, is_active, rate_limit_per_minute,
+                       created_at, total_requests, total_tokens, total_cost
+                FROM clients WHERE client_id = ?
+                "#,
+            )
+            .bind(&id)
+            .fetch_one(pool)
+            .await;
+
+            match row {
+                Ok(row) => Json(ApiResponse::success(serde_json::json!({
+                    "id": row.get::<String, _>("id"),
+                    "name": row.get::<Option<String>, _>("name").unwrap_or_else(|| "Unnamed".to_string()),
+                    "description": row.get::<Option<String>, _>("description"),
+                    "is_active": row.get::<bool, _>("is_active"),
+                    "rate_limit_per_minute": row.get::<Option<i64>, _>("rate_limit_per_minute"),
+                    "created_at": row.get::<chrono::DateTime<chrono::Utc>, _>("created_at"),
+                    "total_requests": row.get::<i64, _>("total_requests"),
+                    "total_tokens": row.get::<i64, _>("total_tokens"),
+                    "total_cost": row.get::<f64, _>("total_cost"),
+                    "status": if row.get::<bool, _>("is_active") { "active" } else { "inactive" },
+                }))),
+                Err(e) => {
+                    warn!("Failed to fetch updated client: {}", e);
+                    // Update succeeded but fetch failed — still report success
+                    Json(ApiResponse::success(serde_json::json!({ "message": "Client updated" })))
+                }
+            }
+        }
+        Err(e) => {
+            warn!("Failed to update client: {}", e);
+            Json(ApiResponse::error(format!("Failed to update client: {}", e)))
+        }
+    }
+}
+
 pub(super) async fn handle_delete_client(
     State(state): State<DashboardState>,
     Path(id): Path<String>,