ci: add mypy job + pre-commit hook, tighten type annotations
- .github/workflows/ci.yml: new 'types' job runs mypy src/; docker now needs lint+types+test
- .pre-commit-config.yaml: add mirrors-mypy hook on src/ with types-requests, types-PyYAML
- pyproject.toml: add per-module overrides ignoring legacy modules (main, downloader, reddit_client, database, extractors.{reddit,gfycat}) while keeping src/web/ strict
- src/web/deps.py: type DOWNLOADS_DIR explicitly as Path
- src/web/config_manager.py: type guards on get_subreddits/users/blacklist returns
- src/web/routers/favorites.py: dict[str, object] for result, avoid in-place + on object
- src/web/routers/media.py: dict[str, object] for delete result
- src/web/rate_limit.py: move Awaitable/Callable under TYPE_CHECKING
- ruff format + auto-fix on src/ + tests/
Richard Nixon
b4a2f303ac