Task #609: Per-user app enable/disable in Settings

- New `user_hidden_apps` table (userId+appId composite PK, cascade) in
  lib/db/src/schema/user-hidden-apps.ts; registered in schema index;
  pushed to dev DB via drizzle-kit.
- Backend (artifacts/api-server/src/routes/apps.ts):
  - GET /me/apps — returns every globally-active app visible to the
    user with a `hidden` flag.
  - PUT /me/apps/:appId/hidden — toggles a row in user_hidden_apps,
    gated by getVisibleAppsForUser + isActive so a user can't toggle
    apps they can't reach.
  - GET /apps (Home/Dock) now uses getVisibleNonHiddenAppsForUser so
    hidden apps disappear immediately.
- lib/appsVisibility.ts: added getHiddenAppIdsForUser and
  getVisibleNonHiddenAppsForUser helpers.
- OpenAPI: added /me/apps + /me/apps/{appId}/hidden, MyApp and
  UpdateMyAppHiddenBody schemas; regenerated api-zod + api-client-react.
- Frontend (settings-panel.tsx): added "My apps" accordion section as
  first GroupItem with MyAppsBody — Switch per app, optimistic update,
  invalidates getListMyAppsQueryKey + getListAppsQueryKey so Home/Dock
  refresh without reload.
- Translations: added settingsPanel.section.myApps + settingsPanel.myApps
  in ar.json + en.json.
- Code review fix: /me/apps and PUT gating filter isActive even for
  admins, so inactive apps don't appear in the Settings list.
- Proposed follow-up #611 (Playwright test that hidden apps disappear
  from Home and Dock).

lib/api-spec/openapi.yaml

@@ -633,6 +633,64 @@ paths:
               schema:
                 $ref: "#/components/schemas/ErrorResponse"
 
+  /me/apps:
+    get:
+      operationId: listMyApps
+      tags: [apps]
+      summary: List apps for the current user with their per-user hidden state
+      description: |
+        Returns every globally active app (regardless of the per-user hidden
+        flag), each with a `hidden` boolean indicating whether the current
+        user has hidden it from their own Home/Dock via PUT /me/apps/{appId}/hidden.
+        Used by the per-user Settings panel; the Home and Dock continue to use
+        GET /apps which already filters out hidden apps server-side.
+      responses:
+        "200":
+          description: Apps visible to the current user, with per-user hidden state
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/MyApp"
+
+  /me/apps/{appId}/hidden:
+    put:
+      operationId: updateMyAppHidden
+      tags: [apps]
+      summary: Hide or show an app for the current user
+      parameters:
+        - name: appId
+          in: path
+          required: true
+          schema:
+            type: integer
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/UpdateMyAppHiddenBody"
+      responses:
+        "200":
+          description: Updated per-user app state
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/MyApp"
+        "400":
+          description: Validation error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorResponse"
+        "404":
+          description: App not found or not visible to the current user
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorResponse"
+
   # Settings
   /settings:
     get:
@@ -4231,6 +4289,23 @@ components:
           type: string
           format: date-time
 
+    MyApp:
+      allOf:
+        - $ref: "#/components/schemas/App"
+        - type: object
+          required: [hidden]
+          properties:
+            hidden:
+              type: boolean
+              description: True when the current user has hidden this app from their Home/Dock.
+
+    UpdateMyAppHiddenBody:
+      type: object
+      required: [hidden]
+      properties:
+        hidden:
+          type: boolean
+
     UpdateMyAppOrderBody:
       type: object
       required: [order]