24 switch to ruff

[nickmoreton]

Summary

Replace black, flake8, and isort with ruff for faster, unified code formatting and linting.

Changes

• pyproject.toml: Added ruff configuration (88 char line length, Python 3.10+) and updated dev dependencies
• .pre-commit-config.yaml: Replaced three hooks with ruff and ruff-format
• setup.cfg: Deleted (no longer needed)
• CLAUDE.md: Updated documentation
• Formatted one file: app/home/management/commands/create_sample_media.py

Validation

• uv sync - ruff v0.14.10 installed
• ruff check app/ - passed
• ruff format --check app/ - passed
• pre-commit run --all-files - passed

Migration Steps

uv sync
pre-commit install
pre-commit run --all-files