refactor: 统一 log.ts/debug.ts 的测试 mock 为共享定义

- 新增 tests/mocks/log.ts 和 tests/mocks/debug.ts，覆盖源文件全部实际导出
- 移除旧 mock 中不存在的导出（logToFile、logEvent、getLogFilePath）
- 13 个测试文件改为使用共享 mock，避免定义分散和不一致

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/services/langfuse/__tests__/langfuse.test.ts

@@ -1,4 +1,5 @@
 import { mock, describe, test, expect, beforeEach } from 'bun:test'
+import { debugMock } from '../../../../tests/mocks/debug'
 
 // Mock @langfuse/otel before any imports
 const mockForceFlush = mock(() => Promise.resolve())
@@ -71,9 +72,7 @@ mock.module('@langfuse/tracing', () => ({
 }))
 
 // Mock debug logger
-mock.module('src/utils/debug.ts', () => ({
-  logForDebugging: mock(() => {}),
-}))
+mock.module('src/utils/debug.ts', debugMock)
 
 // Mock user data — resolveLangfuseUserId uses getCoreUserData().email and .deviceId
 mock.module('src/utils/user.js', () => ({

src/services/mcp/__tests__/officialRegistry.test.ts

@@ -1,11 +1,10 @@
 import { mock, describe, expect, test, afterEach } from "bun:test";
+import { debugMock } from "../../../../tests/mocks/debug";
 
 mock.module("axios", () => ({
   default: { get: async () => ({ data: { servers: [] } }) },
 }));
-mock.module("src/utils/debug.ts", () => ({
-  logForDebugging: () => {},
-}));
+mock.module("src/utils/debug.ts", debugMock);
 
 const { isOfficialMcpUrl, resetOfficialMcpUrlsForTesting } = await import(
   "../officialRegistry"