feat: Add /tools page with centralized tool registry management

- Add ToolsPage for managing MCP tools activation and persistence
- Centralize all tool handlers in services/tools/handlers/
- toolRegistry.ts is now the single source of truth for tool state
- Add tools store for pinned tools (persisted in localStorage)
- Tools can be pinned to stay active across page navigation
- Remove old individual tool files, replaced by centralized handlers

frontend/src/App.vue

@@ -14,7 +14,7 @@ const router = useRouter()
 const showTerminal = ref(false)
 const canvasStore = useCanvasStore()
 
-type PageName = 'home' | 'canvas' | 'components' | 'themes' | 'projects' | 'project-canvas' | 'database' | 'source' | 'terminal'
+type PageName = 'home' | 'canvas' | 'components' | 'themes' | 'projects' | 'project-canvas' | 'database' | 'source' | 'terminal' | 'tools'
 
 onMounted(async () => {
   // Initialize WebMCP connection