feat: Add dynamic MCP tool registration per page

- webmcp.ts: Add tool tracking, unregisterTool(), clearAllTools()
- tools/canvasTools.ts: render_html, render_vue_component
- tools/componentTools.ts: save/load/list/delete_vue_component
- tools/themeTools.ts: get_design_tokens, get_active_theme, set_theme_variable, save_theme
- tools/globalTools.ts: get_current_page, navigate_to, list_available_tools
- toolRegistry.ts: Orchestrates tool registration per page
- App.vue: Initializes WebMCP once, watches route for tool changes
- Canvas.vue: Removed tool registration (now handled by registry)

Tools are now registered when entering a page and unregistered when leaving.
Refresh initializes tools correctly for the current page.

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

frontend/src/components/Canvas.vue

@@ -1,7 +1,5 @@
 <script setup lang="ts">
 import { onMounted, onUnmounted } from 'vue'
-import { initWebMCP } from '../services/webmcp'
-import { registerCanvasTools } from '../services/canvasTools'
 import { renderInlineComponent, type VueComponentDefinition } from '../services/dynamicComponents'
 import { useCanvasStore } from '../stores/canvas'
 
@@ -34,11 +32,8 @@ function handleLoadComponent(e: Event) {
   canvasStore.addToHistory({ tool: 'load_vue_component', args: detail, timestamp: Date.now() })
 }
 
-onMounted(async () => {
+onMounted(() => {
   window.addEventListener('load-vue-component', handleLoadComponent)
-
-  await initWebMCP()
-  registerCanvasTools()
 })
 
 onUnmounted(() => {