[Adarsh2709]

Summary of Changes

This PR includes fixes for CI pipeline execution, backend test discovery, module pollution prevention, and security route checks:

1. CI/CD Workflow:

   • Fixed the pip cache dependency path in .github/workflows/ci.yml.
   • Ensured PYTHONPATH=. is set during test execution so backend module imports resolve cleanly.

2. Backend Module Resolution:

   • Added package __init__.py files across backend directories to ensure standardized package discovery.

3. Test Stability & Isolation:

   • Resolved global boto3 client mocking pollution in tests so test cases don't interfere with each other.
   • Updated end-to-end assertions to match current status outputs.

4. Security & Access Control:

   • Enforced require_editor permission checks on /deploy and /revert endpoints.
   • Updated E2E test assertions to reflect role-based access enforcement.

5. Repository Cleanliness:

   • Added build_lambda/ and *.zip to .gitignore to avoid checking in build and packaging artifacts.