chore(tests): bootstrap pytest infra + CI guards

[isac322]

Why

Shared infrastructure for the backend overhaul series (pytest + CI grep guards + docs-seo trigger update).

What

• tests/conftest.py: virtual_session fixture (Session.start/stop)
• tests/test_smoke.py: D-Bus reachability check
• pyproject.toml: pytest>=8.0, pytest-asyncio>=0.23 dev deps + [tool.pytest.ini_options] (@pytest.mark.kwin marker)
• scripts/ci_guards.sh: 4 grep guards
  1. No print() reachable from MCP server paths
  2. Every kwin_wayland invocation must include --virtual
  3. No module-top accessibility_worker import in core.py (Pool worker isolation invariant)
  4. No os.fork / multiprocessing.Process( (spawn context only)
  • Excludes non-launch references (pkill / --version / echo)
• .github/workflows/ci.yml: guards job
• CLAUDE.md: docs-seo trigger table extended with dbus_args.py, window.py, accessibility_worker.py, docs/design/*.md

Verify

uv run pytest tests/test_smoke.py        # → 1 passed
bash scripts/ci_guards.sh                # → all 4 pass

---

Series: Part of a 7-PR series. PR 0/1/1b are based on main (parallel), PR 2–5 are stacked. Merge order: PR 0 → (1, 1b in parallel) → 2 → 3 → 4 → 5.

[github-actions]

📝 Docs & SEO Review

Source files changed in this PR:

pyproject.toml

Consistency check results:

✅  All documentation/plugin SEO checks passed.

Run @docs-seo in Claude Code to perform a full documentation review.