Migrate frontend to Vite + Hono CopilotKit runtime

Replaces the Next.js scaffold with a Vite SPA paired with a Hono
sidecar that hosts the CopilotKit runtime and proxies AG-UI traffic
to the MAF backend. Adds dev/prod Dockerfile, .dockerignore,
.gitignore, pnpm workspace config, and updates entrypoints
(main.tsx / App.tsx / index.css / index.html) plus the service
worker accordingly.

Server middleware reconciles MAF MESSAGES_SNAPSHOT id mismatches
so post-tool-call assistant text doesn't render twice, suppresses
duplicate text emitted alongside render tools, and strips OpenAI
training-token leaks from streamed deltas.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/vite.config.ts

@@ -1,19 +1,25 @@
-import { defineConfig } from 'vite';
-import react from '@vitejs/plugin-react-swc';
-import tailwindcss from '@tailwindcss/vite';
-import path from 'path';
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react-swc";
+import tailwindcss from "@tailwindcss/vite";
+import path from "path";
 
 export default defineConfig({
   plugins: [react(), tailwindcss()],
   resolve: {
     alias: {
-      '@': path.resolve(__dirname, './src'),
+      "@": path.resolve(__dirname, "./src"),
     },
   },
   server: {
     proxy: {
-      '/api': {
-        target: 'http://localhost:8001',
+      // CopilotKit runtime (Hono server, dev only)
+      "/api/copilotkit": {
+        target: "http://localhost:3001",
+        changeOrigin: true,
+      },
+      // All other API calls → Python backend
+      "/api": {
+        target: "http://localhost:8001",
         changeOrigin: true,
       },
     },