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/auto-slash-command/executor-resolution.test.ts

@@ -1,4 +1,4 @@
-import { describe, expect, it, mock } from "bun:test"
+import { afterAll, describe, expect, it, mock } from "bun:test"
 import type { LoadedSkill } from "../../features/opencode-skill-loader"
 
 mock.module("../../shared", () => ({
@@ -27,6 +27,10 @@ mock.module("../../features/opencode-skill-loader", () => ({
   discoverAllSkills: async (): Promise<LoadedSkill[]> => [],
 }))
 
+afterAll(() => {
+  mock.restore()
+})
+
 const { executeSlashCommand } = await import("./executor")
 
 function createRestrictedSkill(): LoadedSkill {