Add Ruff checking to replace pylint flake8 black and isort, add prek as tooling for local checks, add vscode settings

[aryanhasgithub]

What does this implement/fix?

Replace Black/isort/flake8/pylint with Ruff, add prek for local hook enforcement

Summary

Consolidates the Python lint/format toolchain onto Ruff, replacing Black, isort, flake8, and pylint. Adds prek (Rust-based pre-commit) to run lint + tests automatically on every commit.

Tooling changes

• pyproject.toml: [tool.black] and [tool.isort] replaced with [tool.ruff] / [tool.ruff.lint] / [tool.ruff.format]. [tool.pylint.*] sections removed entirely. ruff and prek added to dev extras; black, isort, flake8, pylint, autopep8 removed. Ruff's PL (pylint-equivalent) and B (bugbear) rule sets are enabled, with an ignore list mirroring the checks previously disabled in [tool.pylint."MESSAGES CONTROL"] so effective strictness is preserved.
• setup.cfg: removed the now-unused [flake8] section.
• script/lint_flake8 → script/lint_ruff: renamed and rewritten to run ruff check --fix + ruff format instead of flake8.
• script/lint_black, script/lint_isort, script/lint_pylint: deleted.
• script/lint: updated to call lint_ruff + lint_mypy only.
• mypy is kept as-is for type checking (unrelated to this migration) — fixed a config typo in mypy.ini (python_version >= 3.11 → python_version = 3.13, the >= was invalid .ini syntax and was silently failing to parse).

New: prek for automatic local enforcement

• .pre-commit-config.yaml (new): defines two local hooks — lint (./script/lint) and tests (./script/tests, always_run: true) — both run on every commit.
• script/setup: now runs prek install (and pre-push hook type) automatically as part of --dev setup, so hooks are wired up with zero manual steps for anyone setting up the repo fresh.

VS Code workspace config

• .vscode/settings.json: removed legacy python.linting.* keys (flake8/mypy linting, python.pythonPath, python.formatting.provider); added Ruff as the default formatter with format-on-save + fix-on-save, Pylance typeCheckingMode: "standard", and pylint.enabled: false.
• .vscode/launch.json: switched the run config from "type": "python" / program: __main__.py to "type": "debugpy" / module: linux_voice_assistant — fixes a real bug where launching the script directly caused linux_voice_assistant/zeroconf.py to shadow the installed zeroconf package (ModuleNotFoundError: No module named 'zeroconf.asyncio').
• .vscode/extensions.json: added charliermarsh.ruff to recommendations.

Docs

• AGENTS.md, README.md, .github/CONTRIBUTING.md, .github/PULL_REQUEST_TEMPLATE.md: updated all lint/test command references from ./script/lint / ./script/tests to prek run lint --all-files / prek run tests --all-files.

CI

• .github/workflows/lint.yml: removed the separate lint_black, lint_flake8, lint_isort jobs. lint_pylint job renamed to lint_ruff, now runs ./script/lint_ruff. lint_mypy job unchanged.

Minor code fixes (surfaced by Ruff/mypy during migration)

• linux_voice_assistant/models.py: setattr(oww_model, "wake_word", ...) → direct attribute assignment with # type: ignore[attr-defined] — OpenWakeWord (from pyopen_wakeword) doesn't declare this attribute; confirmed via dir() inspection that it's not part of the class's real interface, suppressed rather than removed since downstream behavior wasn't investigated further.
• linux_voice_assistant/entity.py: simplified a nested if/else into elif (Ruff auto-fix).
• Several files: removed stray blank lines after class/with/if openers (Ruff formatter).
• tests/unit/test_unit.py: import linux_voice_assistant.util as util → from linux_voice_assistant import util (Ruff import-style fix, applied consistently across all occurrences).

Testing

• prek run --all-files passes (Ruff + mypy).
• prek run tests --all-files — all 294 tests pass.

Related issue (if applicable):

• Fixes #

Types of changes

• Dependencies bump — dependencies
• Bugfix (non-breaking change which fixes an issue) — bugfix
• New feature (non-breaking change which adds functionality) — new-feature
• Enhancement to an existing feature — enhancement
• Breaking change (fix or feature that would cause existing functionality to not work as expected) — breaking-change
• Refactor (no behaviour change) — refactor
• Documentation only — documentation
• Maintenance / chore — maintenance
• CI / workflow change — ci

Checklist

• The code change is tested and works locally.
• ./script/lint passes.
• ./script/tests passes, and tests have been added/updated under tests/ where applicable.