What's new
- Fixed: Dockerfile was hardcoding pip dependencies instead of installing from requirements.txt — now uses COPY requirements.txt + pip install -r for proper layer caching
- Fixed: CI workflow hardcoded pip install flask pytest instead of using requirements-dev.txt
- Fixed: requirements-dev.txt only contained pytest — added flask and watchdog so it reflects what tests actually need
- Added: pyproject.toml with project metadata and pytest configuration