refactor: reorganize Control Room navigation

- Consolidate Containers and Proxy Hosts under "Stack" section
- Add "Data Management" section with database browser placeholders:
  PostgreSQL, Redis, Qdrant, Neo4j
- Remove unused nav items: Networks, Volumes, Images (Portainer),
  Redirections, Streams, Certificates (NPM)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/features/control_room/presentation/pages/control_room_page.dart

@@ -69,44 +69,11 @@ class _SectionContent extends ConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
-    switch (nav) {
-      case ControlRoomNav.containers:
-        return const _ContainersSection();
-      case ControlRoomNav.proxyHosts:
-        return const ProxyHostsPage();
-      default:
-        return _PlaceholderSection(nav: nav);
-    }
-  }
-}
-
-/// Containers section with optional stack filter.
-class _ContainersSection extends ConsumerWidget {
-  const _ContainersSection();
-
-  @override
-  Widget build(BuildContext context, WidgetRef ref) {
-    final selectedStack = ref.watch(selectedStackProvider);
-    final colorScheme = Theme.of(context).colorScheme;
-
-    return Row(
-      children: [
-        // Stacks filter panel
-        const _StacksFilterPanel(),
-        // Divider
-        VerticalDivider(
-          width: 1,
-          thickness: 1,
-          color: colorScheme.outlineVariant,
-        ),
-        // Main content - containers list or stack detail
-        Expanded(
-          child: selectedStack == null
-              ? const ContainersListPage()
-              : StackDetailPage(stackId: selectedStack),
-        ),
-      ],
-    );
+    return switch (nav) {
+      ControlRoomNav.containers => const _ContainersSection(),
+      ControlRoomNav.proxyHosts => const ProxyHostsPage(),
+      _ => _PlaceholderSection(nav: nav),
+    };
   }
 }
 
@@ -150,6 +117,36 @@ class _PlaceholderSection extends StatelessWidget {
   }
 }
 
+/// Containers section with optional stack filter.
+class _ContainersSection extends ConsumerWidget {
+  const _ContainersSection();
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final selectedStack = ref.watch(selectedStackProvider);
+    final colorScheme = Theme.of(context).colorScheme;
+
+    return Row(
+      children: [
+        // Stacks filter panel
+        const _StacksFilterPanel(),
+        // Divider
+        VerticalDivider(
+          width: 1,
+          thickness: 1,
+          color: colorScheme.outlineVariant,
+        ),
+        // Main content - containers list or stack detail
+        Expanded(
+          child: selectedStack == null
+              ? const ContainersListPage()
+              : StackDetailPage(stackId: selectedStack),
+        ),
+      ],
+    );
+  }
+}
+
 /// Stacks filter panel for Containers section (includes "All Containers" option).
 class _StacksFilterPanel extends ConsumerWidget {
   const _StacksFilterPanel();