Two critical bugs found by API integration tests:
1. contacts.embedding (vector(768)) — ORM model updated in Phase 5.3 but
plugin migration 0002_embeddings.sql was never run as Alembic migration.
Also adds embedding columns to mails, companies, files, calendar_entries, tags.
2. audit_log.created_at, updated_at, deleted_at — AuditLog inherits TenantMixin
which expects these columns, but they were never added to the DB table.
Also adds to deletion_log.
Migration uses IF NOT EXISTS checks for all columns/indexes.
Alembic head: 0103 → 0104
Agent Zero