Refactor UI modules and harden run/API behavior

package.json

@@ -10,7 +10,8 @@
     "test": "node --import tsx/esm --test tests/**/*.test.ts",
     "verify": "npm run check && npm run check:tests && npm run test && npm run build",
     "dev": "node --import tsx/esm src/index.ts",
-    "ui": "node --import tsx/esm src/ui/server.ts",
+    "ui:build": "npm --prefix ui run build",
+    "ui": "npm run ui:build && node --import tsx/esm src/ui/server.ts",
     "codex": "node --import tsx/esm src/examples/codex.ts",
     "claude": "node --import tsx/esm src/examples/claude.ts",
     "start": "node dist/index.js"
@@ -29,11 +30,16 @@
   "dependencies": {
     "@anthropic-ai/claude-agent-sdk": "^0.2.50",
     "@openai/codex-sdk": "^0.104.0",
+    "cors": "^2.8.6",
     "dotenv": "^17.3.1",
+    "express": "^5.2.1",
+    "lowdb": "^7.0.1",
     "sh-syntax": "^0.5.8",
     "zod": "^4.3.6"
   },
   "devDependencies": {
+    "@types/cors": "^2.8.19",
+    "@types/express": "^5.0.6",
     "@types/node": "^25.3.0",
     "tsx": "^4.21.0",
     "typescript": "^5.9.3"