refactor(tools): remove native ast-grep tool

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/tools/index.ts

@@ -1,4 +1,3 @@
-export { createAstGrepTools } from "./ast-grep"
 export { createGrepTools } from "./grep"
 export { createGlobTools } from "./glob"
 export { createSkillTool } from "./skill"