feat(mcp): register ast-grep as built-in MCP

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

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

src/mcp/index.ts

@@ -1,6 +1,7 @@
 import { createWebsearchConfig } from "./websearch"
 import { context7 } from "./context7"
 import { grep_app } from "./grep-app"
+import { createAstGrepMcpConfig } from "./ast-grep"
 import { createLspMcpConfig, type LocalMcpConfig } from "./lsp"
 import type { OhMyOpenCodeConfig } from "../config/schema"
 
@@ -16,7 +17,11 @@ type RemoteMcpConfig = {
 
 type BuiltinMcpConfig = RemoteMcpConfig | LocalMcpConfig
 
-export function createBuiltinMcps(disabledMcps: string[] = [], config?: OhMyOpenCodeConfig) {
+type BuiltinMcpOptions = {
+  readonly cwd?: string
+}
+
+export function createBuiltinMcps(disabledMcps: string[] = [], config?: OhMyOpenCodeConfig, options: BuiltinMcpOptions = {}) {
   const mcps: Record<string, BuiltinMcpConfig> = {}
 
   if (!disabledMcps.includes("websearch")) {
@@ -38,5 +43,9 @@ export function createBuiltinMcps(disabledMcps: string[] = [], config?: OhMyOpen
     mcps.lsp = createLspMcpConfig()
   }
 
+  if (!disabledMcps.includes("ast_grep")) {
+    mcps.ast_grep = createAstGrepMcpConfig({ cwd: options.cwd, disabledTools: config?.disabled_tools })
+  }
+
   return mcps
 }