feat(tools): add ast-grep tools for AST-aware code search and transformation

- Add ast_grep_search for pattern-based code search (25 languages)
- Add ast_grep_replace for AST-aware code rewriting with dry-run
- Add ast_grep_analyze for in-memory code analysis (NAPI)
- Add ast_grep_transform for in-memory code transformation
- Add ast_grep_languages to list supported languages

package.json

@@ -40,6 +40,7 @@
   },
   "homepage": "https://github.com/code-yeongyu/oh-my-opencode#readme",
   "dependencies": {
+    "@ast-grep/napi": "^0.40.0",
     "@opencode-ai/plugin": "^1.0.7"
   },
   "devDependencies": {