Layer 1: Pre-commit hook (scripts/check_no_binaries.sh) blocks 60+
binary/image extensions with .binary-allowlist for build-essential exceptions.
Layer 2: Comprehensive .gitignore binary patterns with ! overrides
for allowlisted files (app icons).
Layer 3: Agent exclusions - .copilotignore, files.exclude, and
search.exclude all mirror the same patterns to prevent Copilot
from hitting the 20-image URL limit.
- Move puzzle_solver/, poker_modifier_app/, articles/, tests/ into python_pkg/
- Move moviepy_showcase.py and _moviepy_*.py into python_pkg/moviepy_showcase/
- Update all imports to use python_pkg. prefix
- Update pyproject.toml per-file-ignores and pytest testpaths
- Add pre-commit hook to enforce Python files under python_pkg/
