Backend suite is the slow gate (1076 passed locally in 22m27s on
fix/ci-workflow-config). Adding pytest-xdist with per-worker DB
isolation drops it to ~4m20s on the 8-core homelab runner. Verified
locally: `pytest -n auto --no-cov` finished in 4m28s real time
(15m19s user — confirms ~5× parallelism).
How it works:
- conftest.py reads `PYTEST_XDIST_WORKER` (set per worker by xdist —
'gw0', 'gw1', …). When set, derives a per-worker DB URL like
`…/resolutionflow_test_gw0`. The base DB stays for serial / master
runs.
- `_ensure_worker_db_exists` runs synchronously at conftest import,
connects to the postgres maintenance DB, and `CREATE DATABASE`s the
worker-suffixed DB if it doesn't exist. Idempotent across runs.
- The "test" safety guard still applies — every worker DB name
contains "test" so the assertion holds.
- The per-test `DROP SCHEMA public CASCADE` now operates on the
worker's isolated DB, no cross-worker race.
CI workflow: backend job switches to `pytest -n auto`. Coverage still
collected (pytest-cov has built-in xdist support).
Adds `pytest-xdist==3.6.1` to requirements-dev.txt.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
