chore: 添加 builtin-tools 路径别名至 tsconfig，更新 bun.lock

- tsconfig.json 新增 builtin-tools/* 和 builtin-tools 路径映射
- 新增 packages/builtin-tools/src 至 include

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: claude-code-best

bun.lock

@@ -12,9 +12,11 @@
         "resolveJsonModule": true,
         "types": ["bun"],
         "paths": {
-            "src/*": ["./src/*"]
+            "src/*": ["./src/*"],
+            "builtin-tools/*": ["./packages/builtin-tools/src/*"],
+            "builtin-tools": ["./packages/builtin-tools/src/index.ts"]
         }
     },
-    "include": ["src/**/*.ts", "src/**/*.tsx"],
+    "include": ["src/**/*.ts", "src/**/*.tsx", "packages/builtin-tools/src/**/*.ts", "packages/builtin-tools/src/**/*.tsx"],
     "exclude": ["node_modules"]
 }