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/atlas/session-last-agent.sqlite.test.ts

@@ -1,4 +1,4 @@
-const { describe, expect, mock, test } = require("bun:test")
+const { describe, expect, mock, test, afterAll } = require("bun:test")
 
 mock.module("../../shared/opencode-message-dir", () => ({
   getMessageDir: () => null,
@@ -12,6 +12,8 @@ mock.module("../../shared/normalize-sdk-response", () => ({
   normalizeSDKResponse: <TData>(response: { data?: TData }, fallback: TData): TData => response.data ?? fallback,
 }))
 
+afterAll(() => { mock.restore() })
+
 const { getLastAgentFromSession } = await import("./session-last-agent")
 
 function createMockClient(messages: Array<{ info?: { agent?: string } }>) {