feat: Visual CoPilot module + collapsible sidebar

- Add visual-copilot module (iframe embed, env: NEXT_PUBLIC_VIM_URL)
- Sidebar collapse to icon-only with localStorage persistence
- Tooltips on collapsed nav items
- Full-viewport layout for canvas routes (/visual-copilot)
- Register module in modules.ts + feature flag in flags.ts

src/config/flags.ts

@@ -98,6 +98,14 @@ export const DEFAULT_FLAGS: FeatureFlag[] = [
     category: "module",
     overridable: true,
   },
+  {
+    key: "module.visual-copilot",
+    enabled: true,
+    label: "Visual CoPilot",
+    description: "Canvas AI pentru vizualizare arhitecturală",
+    category: "module",
+    overridable: true,
+  },
   {
     key: "module.hot-desk",
     enabled: true,