Fix MCP server entry point

Update start script and Dockerfile CMD to use index.mjs generated by tsup ESM build

apps/mcp/Dockerfile

@@ -11,4 +11,4 @@ COPY --from=build /app/dist ./dist
 COPY --from=build /app/node_modules ./node_modules
 COPY --from=build /app/package.json .
 EXPOSE 3000
-CMD ["node", "dist/index.js"]
+CMD ["node", "dist/index.mjs"]

apps/mcp/package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "dev": "tsx watch src/index.ts",
     "build": "tsup src/index.ts --format esm --clean",
-    "start": "node dist/index.js",
+    "start": "node dist/index.mjs",
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {