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/features/background-agent/manager.test.ts

@@ -1,5 +1,5 @@
 declare const require: (name: string) => any
-const { describe, test, expect, beforeEach, afterEach, spyOn, mock } = require("bun:test")
+const { describe, test, expect, beforeEach, afterEach, afterAll, spyOn, mock } = require("bun:test")
 
 mock.module("../../shared/connected-providers-cache", () => ({
   readConnectedProvidersCache: () => null,
@@ -10,6 +10,8 @@ mock.module("../../shared/connected-providers-cache", () => ({
   updateConnectedProvidersCache: () => {},
 }))
 
+afterAll(() => { mock.restore() })
+
 import { getSessionPromptParams, clearSessionPromptParams } from "../../shared/session-prompt-params-state"
 import { tmpdir } from "node:os"
 import type { PluginInput } from "@opencode-ai/plugin"