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/shared/opencode-message-dir.test.ts

@@ -19,6 +19,8 @@ mock.module("./opencode-storage-detection", () => ({
   resetSqliteBackendCache: () => {},
 }))
 
+afterAll(() => { mock.restore() })
+
 const { getMessageDir } = await import("./opencode-message-dir")
 
 describe("getMessageDir", () => {