ruff --fix removed the TaskSpec import as unused within the module,
but it is part of the public API — tests import it from scripts.task_scheduler
rather than reaching into circuitforge_core directly.
Add # noqa: F401 to protect intentional re-exports from future auto-fix.
Forgejo reserves the GITHUB_* prefix for secret names — creating a secret
called GITHUB_MIRROR_TOKEN returns 'invalid secret name'.
Also rename the GITHUB_TOKEN step env var to GH_MIRROR_PAT to avoid
collision with the built-in Forgejo Actions context variable.
- Add pyproject.toml with ruff per-file-ignores:
- Exclude deprecated app/ Streamlit dir entirely
- Suppress E702 in dev-api.py (intentional compact Pydantic models)
- Suppress E402 in finetune_local.py (conditional ML imports after CUDA check)
- Suppress F841/E741/E702 in tests/ (mock-patch capture pattern)
- Remove unused db_path_obj assignment in dev-api.py:760
- Add # noqa: E402 to documented mid-file imports in dev-api.py
- Rename ambiguous l variable to line/lbl in finetune_local.py + label_tool.py
