feat(dashboard): add canvas view with active deployment overlay

Add a /dashboard/canvas page that renders every team server with its
resources and their running or queued deployments, backed by a new
ServerCanvasController::dashboard endpoint and a per-server usage
endpoint for zone headers. The dashboard remembers the list/canvas
choice and each section (projects, servers) its own table/grid view.

- Show Deploying/Queued pills on canvas cards and a foldable recent
  deployments panel; add shared CanvasControls component
- Allow backup downloads from the server host via the S3 download
  storage (PrepareFileDownloadJob accepts a null container)
- Extract backup toggle/run actions into ManagesDatabaseBackup and
  surface them in backup execution headers; merge S3 and retention
  sections into the general backup settings
- Move deployments indicator to the top bar and add a main nav
  resource menu with submenus; simplify breadcrumbs and settings
  layouts
- Add shared variables overview canvas and scheduled task modals
- Add feature tests for dashboard canvas, view modes, navbar
  submenus, backup S3 downloads and scheduled task modals

app/Http/Controllers/Api/ServerCanvasController.php

@@ -29,6 +29,22 @@ class ServerCanvasController extends Controller
         return response()->json($this->canvas->payload($teamId, $servers, null, $this->canReadSensitive($request), $this->canEdit($request, $teamId)));
     }
 
+    /**
+     * Dashboard canvas: every server of the team with its resources and their running or queued deployments.
+     */
+    public function dashboard(Request $request): JsonResponse
+    {
+        $teamId = getTeamIdFromToken();
+        if (is_null($teamId)) {
+            return invalidTokenResponse();
+        }
+        $this->authorize('viewAny', Server::class);
+
+        $servers = Server::query()->whereTeamId($teamId)->with('settings')->orderBy('name')->get();
+
+        return response()->json($this->canvas->dashboardPayload($teamId, $servers, $this->canReadSensitive($request), $this->canEdit($request, $teamId)));
+    }
+
     public function show(Request $request, string $uuid): JsonResponse
     {
         $teamId = getTeamIdFromToken();
@@ -73,6 +89,27 @@ class ServerCanvasController extends Controller
         return response()->json(['nodes' => $this->canvas->unmanagedContainerNodes($server)->all()]);
     }
 
+    /**
+     * Latest CPU, memory and disk usage of one server for its zone header on the canvas.
+     */
+    public function usage(string $uuid): JsonResponse
+    {
+        $teamId = getTeamIdFromToken();
+        if (is_null($teamId)) {
+            return invalidTokenResponse();
+        }
+        $server = Server::query()->whereTeamId($teamId)->whereUuid($uuid)->with('settings')->first();
+        if (! $server) {
+            return response()->json(['message' => 'Server not found.'], 404);
+        }
+        $this->authorize('view', $server);
+        if (! $server->settings->is_metrics_enabled) {
+            return response()->json(['cpu' => null, 'memory' => null, 'disk' => null]);
+        }
+
+        return response()->json($this->canvas->usage($server));
+    }
+
     private function canReadSensitive(Request $request): bool
     {
         return (bool) $request->attributes->get('can_read_sensitive', false);