feat(studio): channel pill in sidebar + Featured strip in Store (v0.20.0)

Sidebar:
- New active-channel pill below the connection pill,
  color-coded so production deployments look visibly
  different from local-dev. Click opens Settings; tooltip
  explains the channel taxonomy. Polled in lockstep with the
  health probe so it tracks CLI-driven `fai channel switch`.

Store:
- Featured strip above the main grid renders editorial
  picks as bigger hero tiles with a subtle gradient
  backdrop, version + status pills, and a one-click
  Install. Hidden the moment the operator types in the
  search box or picks any filter — the result list is the
  answer they want, not editorial chrome.

StoreItem now carries the `featured` flag so the page can
filter without an extra round-trip.

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

lib/main.dart

@@ -23,7 +23,7 @@ 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 = '0.19.0';
+const String kStudioVersion = '0.20.0';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -110,6 +110,7 @@ class StudioShell extends StatefulWidget {
 class _StudioShellState extends State<StudioShell> {
   int _selectedIndex = 0;
   bool? _connected; // null = unknown, polled on a timer
+  String? _activeChannel; // local / dev / beta / production
   Timer? _healthPoll;
 
   static const _pages = <_NavPage>[
@@ -165,6 +166,20 @@ class _StudioShellState extends State<StudioShell> {
     final ok = await HubService.instance.healthy();
     if (!mounted) return;
     if (_connected != ok) setState(() => _connected = ok);
+    // Refresh the active channel pointer alongside the health
+    // probe — cheap, and keeps the sidebar pill honest if the
+    // operator switched channels from the CLI.
+    if (ok) {
+      try {
+        final snap = await HubService.instance.channelStatus();
+        if (!mounted) return;
+        if (_activeChannel != snap.active) {
+          setState(() => _activeChannel = snap.active);
+        }
+      } catch (_) {
+        // Best-effort; pill simply doesn't update this tick.
+      }
+    }
   }
 
   @override
@@ -223,6 +238,7 @@ class _StudioShellState extends State<StudioShell> {
                   pages: _pages,
                   connected: _connected,
                   endpointLabel: HubService.instance.endpointLabel,
+                  activeChannel: _activeChannel,
                 ),
                 Container(
                   width: 1,
@@ -274,6 +290,10 @@ class _Sidebar extends StatelessWidget {
   final List<_NavPage> pages;
   final bool? connected;
   final String endpointLabel;
+  /// Active channel name from the running daemon
+  /// (`local`/`dev`/`beta`/`production`). Null while the
+  /// initial fetch is in flight or the hub is unreachable.
+  final String? activeChannel;
 
   const _Sidebar({
     required this.selectedIndex,
@@ -281,6 +301,7 @@ class _Sidebar extends StatelessWidget {
     required this.pages,
     required this.connected,
     required this.endpointLabel,
+    required this.activeChannel,
   });
 
   @override
@@ -319,6 +340,13 @@ class _Sidebar extends StatelessWidget {
               label: endpointLabel,
             ),
           ),
+          if (activeChannel != null && activeChannel!.isNotEmpty) ...[
+            const SizedBox(height: FaiSpace.sm),
+            Padding(
+              padding: const EdgeInsets.symmetric(horizontal: FaiSpace.lg),
+              child: _ChannelPill(channel: activeChannel!),
+            ),
+          ],
           const SizedBox(height: FaiSpace.xxl),
           // Destinations.
           Expanded(
@@ -370,6 +398,87 @@ class _Sidebar extends StatelessWidget {
   }
 }
 
+/// Active-channel indicator. Click to open Settings (where the
+/// operator can switch). Color-coded so production deployments
+/// look visibly different from local-dev — the kind of thing
+/// you want to see before clicking "Clear log".
+class _ChannelPill extends StatelessWidget {
+  final String channel;
+  const _ChannelPill({required this.channel});
+
+  Color _accent(ColorScheme cs) {
+    switch (channel) {
+      case 'production':
+        return cs.error;
+      case 'beta':
+        return FaiColors.warning;
+      case 'dev':
+        return cs.primary;
+      case 'local':
+      default:
+        return cs.onSurfaceVariant;
+    }
+  }
+
+  IconData get _icon {
+    switch (channel) {
+      case 'production':
+        return Icons.shield_outlined;
+      case 'beta':
+        return Icons.science_outlined;
+      case 'dev':
+        return Icons.bolt_outlined;
+      case 'local':
+      default:
+        return Icons.home_work_outlined;
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final accent = _accent(theme.colorScheme);
+    return Tooltip(
+      message:
+          'Active channel — click to switch in Settings (⌘;).\n'
+          'production = stable · beta = pre-release · dev = rolling · local = workspace',
+      child: Material(
+        color: theme.colorScheme.surfaceContainerHigh,
+        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        child: InkWell(
+          borderRadius: BorderRadius.circular(FaiRadius.sm),
+          onTap: () => FaiSettingsDialog.show(context),
+          child: Container(
+            padding: const EdgeInsets.symmetric(
+              horizontal: FaiSpace.sm,
+              vertical: 4,
+            ),
+            decoration: BoxDecoration(
+              borderRadius: BorderRadius.circular(FaiRadius.sm),
+              border: Border.all(color: accent.withValues(alpha: 0.4)),
+            ),
+            child: Row(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                Icon(_icon, size: 11, color: accent),
+                const SizedBox(width: 4),
+                Text(
+                  channel,
+                  style: FaiTheme.mono(
+                    size: 10,
+                    weight: FontWeight.w600,
+                    color: accent,
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
 class _ConnectionPill extends StatelessWidget {
   final bool? connected;
   final String label;