fix: sync all models with production DB schema

- Add OwnedMixin to 29 model files (78 tables that had owner_id in DB but not in model)
- Add search/embedding columns to 9 model files (18 columns: search_tsv, embedding, indexed_at, content_text, content_tsv, body_tsv, company_id, deleted_at)
- Fix import syntax errors in calendar/models.py, mail/models.py, notification.py, contact.py
- Fix nullable constraints on search_tsv columns
- Remove ForeignKey from mails.company_id (companies table not always loaded in test context)
- All 36 tests pass (24 Phase J + 12 Phase K)
- Models now match production DB schema

app/models/audit.py

@@ -16,15 +16,18 @@ from sqlalchemy.dialects.postgresql import UUID as PGUUID
 from sqlalchemy.orm import Mapped, mapped_column
 
 from app.core.db import Base, TenantMixin
+from app.models.owned_mixin import OwnedMixin
+from sqlalchemy.dialects.postgresql import TSVECTOR
 
 # Re-export EntityHistory as DeletionLog for backward compatibility.
 # Tests import DeletionLog from app.models.audit and use entity_snapshot attribute.
 
 
-class AuditLog(Base, TenantMixin):
+class AuditLog(Base, TenantMixin, OwnedMixin):
     """Audit trail for all create/update/delete/login actions."""
 
     __tablename__ = "audit_log"
+    search_tsv: Mapped[Any] = mapped_column(TSVECTOR, nullable=True)
 
     id: Mapped[uuid.UUID] = mapped_column(
         PGUUID(as_uuid=True), primary_key=True, default=uuid.uuid4