fix(ci): simplify test runner to plain bun test by fixing mock.module() leakage

- Add afterAll(() => { mock.restore() }) to 52 test files missing cleanup
- Rewrite create-tool-guard-hooks.test.ts to use spyOn instead of barrel mock
- Fix skill-mcp-manager OAuth tests with missing mockTokens/mockLogin definitions
- Fix start-work hook: show worktree active block on resume with existing worktree_path
- Extract createWorktreeActiveBlock to worktree-block.ts to avoid circular import
- Replace 80-line isolated test runner CI config with single `bun test` command

src/cli/doctor/checks/system.test.ts

@@ -1,6 +1,6 @@
 /// <reference types="bun-types" />
 
-import { beforeEach, describe, expect, it, mock } from "bun:test"
+import { afterAll, beforeEach, describe, expect, it, mock } from "bun:test"
 import { PLUGIN_NAME } from "../../../shared"
 import type { PluginInfo } from "./system-plugin"
 
@@ -47,6 +47,10 @@ mock.module("./system-loaded-version", () => ({
   getSuggestedInstallTag: mockGetSuggestedInstallTag,
 }))
 
+afterAll(() => {
+  mock.restore()
+})
+
 describe("system check", () => {
   beforeEach(() => {
     mockFindOpenCodeBinary.mockReset()