a222bd4542
Add email-based auto-linking fallback so staff records without a userId are automatically linked on first authenticated request. This fixes a UAT blocker where all authenticated API routes returned HTTP 403 after login because Better-Auth user IDs don't match seed-created staff records. Fallback chain: 1. userId match (existing fast path) 2. oidcSub match (legacy records) 3. email match + auto-link (new)