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/zauc-mocks-mcp-index/index.test.ts

@@ -4,12 +4,19 @@ afterEach(() => {
   mock.restore()
 })
 
+function mockLocalMcps(): void {
+  mock.module("../lsp", () => ({
+    createLspMcpConfig: () => ({ type: "local", command: ["node", "dist/cli.js", "mcp"], enabled: true }),
+  }))
+  mock.module("../ast-grep", () => ({
+    createAstGrepMcpConfig: () => ({ type: "local", command: ["node", "ast-grep-mcp", "mcp"], enabled: true }),
+  }))
+}
+
 describe("createBuiltinMcps", () => {
   test("should return all MCPs when disabled_mcps is empty", () => {
     // given
-    mock.module("../lsp", () => ({
-      createLspMcpConfig: () => ({ type: "local", command: ["node", "dist/cli.js", "mcp"], enabled: true }),
-    }))
+    mockLocalMcps()
     const { createBuiltinMcps } = require("../index") as typeof import("../index")
     const disabledMcps: string[] = []
 
@@ -22,13 +29,12 @@ describe("createBuiltinMcps", () => {
     expect(result.context7).toBeDefined()
     expect(result.grep_app).toBeDefined()
     expect(result.lsp).toBeDefined()
+    expect(result.ast_grep).toBeDefined()
   })
 
   test("should filter out disabled MCPs", () => {
     // given
-    mock.module("../lsp", () => ({
-      createLspMcpConfig: () => ({ type: "local", command: ["node", "dist/cli.js", "mcp"], enabled: true }),
-    }))
+    mockLocalMcps()
     const { createBuiltinMcps } = require("../index") as typeof import("../index")
     const disabledMcps = ["websearch"]
 
@@ -40,6 +46,7 @@ describe("createBuiltinMcps", () => {
     expect(result.context7).toBeDefined()
     expect(result.grep_app).toBeDefined()
     expect(result.lsp).toBeDefined()
+    expect(result.ast_grep).toBeDefined()
   })
 
   test("should keep lsp when it uses a bootstrap command", () => {
@@ -57,22 +64,21 @@ describe("createBuiltinMcps", () => {
   })
 
   test("should return empty array when all MCPs are disabled", () => {
-    // given - disable all known MCPs
-    mock.module("../lsp", () => ({
-      createLspMcpConfig: () => ({ type: "local", command: ["node", "dist/cli.js", "mcp"], enabled: true }),
-    }))
+    // given
+    mockLocalMcps()
     const { createBuiltinMcps } = require("../index") as typeof import("../index")
-    const disabledMcps = ["websearch", "context7", "grep_app", "lsp"]
+    const disabledMcps = ["websearch", "context7", "grep_app", "lsp", "ast_grep"]
 
     // when
     const result = createBuiltinMcps(disabledMcps)
 
-    // then - may still have MCPs we didn't list
+    // then
     const remainingMcpNames = Object.keys(result)
     expect(remainingMcpNames).not.toContain("websearch")
     expect(remainingMcpNames).not.toContain("context7")
     expect(remainingMcpNames).not.toContain("grep_app")
     expect(remainingMcpNames).not.toContain("lsp")
+    expect(remainingMcpNames).not.toContain("ast_grep")
     expect(remainingMcpNames).toEqual([])
   })
 })