feat(core-testing): RecordingJobQueue

Adds RecordingJobQueue implementing IJobQueue for use in unit tests.
Records all enqueue calls with taskSlug/input/options and returns
synthetic incrementing jobIds.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/core-testing/package.json

@@ -21,6 +21,7 @@
     "test": "vitest run"
   },
   "dependencies": {
+    "@repo/core-shared": "workspace:*",
     "@testing-library/jest-dom": "^6.5.0",
     "@testing-library/react": "^16.0.0",
     "@testing-library/user-event": "^14.5.0",