feat: modernize project with uv, add pytest test suite

- Add pyproject.toml with modern Python packaging (PEP 517/518)
- Add uv-based dependency management replacing inline venv bootstrap
- Add requirements.txt and requirements-dev.txt for compatibility
- Add mise.toml with dev tasks (test, lint, run, sync, ci)
- Add .python-version pinned to Python 3.12
- Add comprehensive pytest test suite (73 tests) for:
  - engine/config, filter, terminal, sources, mic, ntfy modules
- Configure pytest with coverage reporting (16% total, 100% on tested modules)
- Configure ruff for linting with Python 3.10+ target
- Remove redundant venv bootstrap code from mainline.py
- Update .gitignore for uv/venv artifacts

Run 'uv sync' to install dependencies, 'uv run pytest' to test.

mise.toml

@@ -0,0 +1,44 @@
+[tools]
+python = "3.12"
+
+[tasks]
+# =====================
+# Development
+# =====================
+
+test = "uv run pytest"
+test-v = "uv run pytest -v"
+test-cov = "uv run pytest --cov=engine --cov-report=term-missing --cov-report=html"
+test-cov-open = "uv run pytest --cov=engine --cov-report=term-missing --cov-report=html && open htmlcov/index.html"
+
+lint = "uv run ruff check engine/ mainline.py"
+lint-fix = "uv run ruff check --fix engine/ mainline.py"
+format = "uv run ruff format engine/ mainline.py"
+
+# =====================
+# Runtime
+# =====================
+
+run = "uv run mainline.py"
+run-poetry = "uv run mainline.py --poetry"
+run-firehose = "uv run mainline.py --firehose"
+
+# =====================
+# Environment
+# =====================
+
+sync = "uv sync"
+sync-all = "uv sync --all-extras"
+install = "uv sync"
+install-dev = "uv sync --group dev"
+
+bootstrap = "uv sync && uv run mainline.py --help"
+
+clean = "rm -rf .venv htmlcov .coverage tests/.pytest_cache"
+
+# =====================
+# CI/CD
+# =====================
+
+ci = "uv sync --group dev && uv run pytest --cov=engine --cov-report=term-missing --cov-report=xml"
+ci-lint = "uv run ruff check engine/ mainline.py"