Raise patch coverage on the v0.14.0 Postgres backend:
- test_db_migrate: _is_superuser plus the full migrate_sqlite_to_postgres
flow (dry-run, copy, non-empty-target refusal, --truncate, missing schema),
routing create_database_engine to SQLite files so a postgresql:// target
satisfies the guard while the run executes SQLite -> SQLite in CI.
- test_main: the `db migrate-to-postgres` CLI command via CliRunner
(success, dry-run, row-count mismatch, ValueError -> ClickException).
- conftest: neutralise dotenv.load_dotenv before collection. Importing the
CLI entrypoint runs load_dotenv() at import time, which leaked a local .env
into os.environ and broke unrelated config/redis tests.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Louis King