NIGHTOWL_ENABLED=false makes the package fully inert (no ingest rebind, no
migration registration) — most useful in the testing environment.
NIGHTOWL_RUN_MIGRATIONS=false stops migrations riding along with the host's
`php artisan migrate` so multiple environments can share one nightowl DB without
"relation already exists" on deploy. nightowl:install now runs migrations via
explicit --path regardless of either flag. Adds MasterSwitchTest + README/config
docs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>