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/hooks/model-fallback/hook.test.ts

@@ -1,5 +1,5 @@
 declare const require: (name: string) => any
-const { beforeEach, describe, expect, mock, test } = require("bun:test")
+const { beforeEach, describe, expect, mock, test, afterAll } = require("bun:test")
 
 const readConnectedProvidersCacheMock = mock(() => null)
 const readProviderModelsCacheMock = mock(() => null)
@@ -53,6 +53,10 @@ mock.module("../../shared/model-error-classifier", () => ({
   selectFallbackProvider: selectFallbackProviderMock,
 }))
 
+afterAll(() => {
+  mock.restore()
+})
+
 import {
   clearPendingModelFallback,
   createModelFallbackHook,