Remove remaining Stori references from pyproject.toml, README, .gitignore, and webhook crypto

- pyproject.toml: "for Stori DAW" → "powered by Muse VCS" - README.md: same description update; "Tellurstori / Stori" → "Muse VCS" - .gitignore: stori.db → muse.db, stori_tourdeforce → muse_tourdeforce - musehub_webhook_crypto.py: STORI_WEBHOOK_SECRET_KEY → MUSE_WEBHOOK_SECRET_KEY - scripts/migrate_webhook_secrets.py: same env var rename - tests/test_musehub_webhooks.py: same env var rename