feat(studio): Cmd+K palette, recent-activity panel, icon/screenshot rendering (v0.21.0)

Three sweeps in a single bundle.

Universal command palette (⌘K / ctrl+K):
- Modal at top-of-window with a single search input. Indexes
  pages, installed modules, store entries, saved flows on
  open; filters client-side as the operator types.
- Keyboard nav (↑/↓ + Enter), grouped sections, hover-to-
  highlight. Hit selection navigates / opens the right
  surface in one keystroke. Closes with Esc.
- Designed to mirror the VSCode / Linear / 1Password
  ergonomics — gives non-CLI operators a "jump anywhere"
  affordance that scales with the number of installed
  modules.

Modules page recent-activity panel:
- Top-of-page strip lists the last 10 install / uninstall
  events from the audit log, color-coded by direction.
  Hidden when no relevant events exist (fresh installs).
  Same locale-unambiguous timestamp format used in audit.

Store detail sheet now renders icons + screenshots:
- `_ModuleIcon` widget loads the explicit `iconUrl` if
  provided, falls back to the category glyph on missing
  URL or load failure (no broken-image rectangle).
- Screenshots strip below the description: 320×200 tiles,
  horizontally-scrollable, click opens full-size via the
  OS handler. Placeholder card on load failure.

StoreItem extended with `iconUrl`, `screenshotUrls`,
`docsUrl` so the new content paths through unchanged.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/main.dart

@@ -19,12 +19,13 @@ import 'pages/modules.dart';
 import 'pages/store.dart';
 import 'theme/theme.dart';
 import 'theme/tokens.dart';
+import 'widgets/fai_search_palette.dart';
 import 'widgets/widgets.dart';
 
 /// Studio's own build version. Bump on every UI commit so the
 /// running app self-identifies — visible in the sidebar header
 /// and quick-glance proof that you're seeing the current build.
-const String kStudioVersion = '0.20.1';
+const String kStudioVersion = '0.21.0';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -189,6 +190,33 @@ class _StudioShellState extends State<StudioShell> {
     super.dispose();
   }
 
+  void _openSearchPalette() {
+    final hits = <FaiSearchHit>[
+      for (var i = 0; i < _pages.length; i++)
+        FaiSearchHit(
+          label: _pages[i].label,
+          hint: 'page · ⌘${i + 1}',
+          icon: _pages[i].icon,
+          group: 'Pages',
+          onSelect: () {
+            Navigator.of(context).pop();
+            setState(() => _selectedIndex = i);
+          },
+        ),
+      FaiSearchHit(
+        label: 'Settings',
+        hint: 'hub endpoint, channels, system AI · ⌘;',
+        icon: Icons.settings_outlined,
+        group: 'Pages',
+        onSelect: () {
+          Navigator.of(context).pop();
+          FaiSettingsDialog.show(context);
+        },
+      ),
+    ];
+    FaiSearchPalette.show(context, staticHits: hits);
+  }
+
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
@@ -212,6 +240,12 @@ class _StudioShellState extends State<StudioShell> {
             const _OpenSettingsIntent(),
         const SingleActivator(LogicalKeyboardKey.comma, meta: true):
             const _OpenSettingsIntent(),
+        // Universal command palette. Mirrors Cmd+K from VSCode /
+        // Linear / 1Password — operators jump anywhere by typing.
+        const SingleActivator(LogicalKeyboardKey.keyK, meta: true):
+            const _OpenSearchIntent(),
+        const SingleActivator(LogicalKeyboardKey.keyK, control: true):
+            const _OpenSearchIntent(),
       },
       child: Actions(
         actions: <Type, Action<Intent>>{
@@ -227,6 +261,12 @@ class _StudioShellState extends State<StudioShell> {
               return null;
             },
           ),
+          _OpenSearchIntent: CallbackAction<_OpenSearchIntent>(
+            onInvoke: (_) {
+              _openSearchPalette();
+              return null;
+            },
+          ),
         },
         child: Focus(
           autofocus: true,
@@ -285,6 +325,10 @@ class _OpenSettingsIntent extends Intent {
   const _OpenSettingsIntent();
 }
 
+class _OpenSearchIntent extends Intent {
+  const _OpenSearchIntent();
+}
+
 class _Sidebar extends StatelessWidget {
   final int selectedIndex;
   final ValueChanged<int> onSelect;