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/plugins/builtins/automation/models.py

@@ -80,7 +80,7 @@ class AgentDefinition(Base, TenantMixin, OwnedMixin):
     )
 
 
-class AgentVersion(Base, TenantMixin):
+class AgentVersion(Base, TenantMixin, OwnedMixin):
     """Versioned snapshots of agent definitions."""
 
     __tablename__ = "automation_agent_versions"
@@ -135,7 +135,7 @@ class AutomationDefinition(Base, TenantMixin, OwnedMixin):
     )
 
 
-class AutomationVersion(Base, TenantMixin):
+class AutomationVersion(Base, TenantMixin, OwnedMixin):
     """Versioned snapshots of automation definitions."""
 
     __tablename__ = "automation_versions"
@@ -160,7 +160,7 @@ class AutomationVersion(Base, TenantMixin):
     )
 
 
-class AutomationCronJob(Base, TenantMixin):
+class AutomationCronJob(Base, TenantMixin, OwnedMixin):
     """Cron job schedule entries for agent heartbeats, automation triggers, or custom jobs."""
 
     __tablename__ = "automation_cron_jobs"
@@ -190,7 +190,7 @@ class AutomationCronJob(Base, TenantMixin):
     )
 
 
-class AgentRun(Base, TenantMixin):
+class AgentRun(Base, TenantMixin, OwnedMixin):
     """Execution log for agent runs."""
 
     __tablename__ = "automation_agent_runs"
@@ -229,7 +229,7 @@ class AgentRun(Base, TenantMixin):
     )
 
 
-class AutomationRun(Base, TenantMixin):
+class AutomationRun(Base, TenantMixin, OwnedMixin):
     """Execution log for automation runs."""
 
     __tablename__ = "automation_runs"
@@ -268,7 +268,7 @@ class AutomationRun(Base, TenantMixin):
     dry_run: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
 
 
-class AgentRunStep(Base, TenantMixin):
+class AgentRunStep(Base, TenantMixin, OwnedMixin):
     """Individual step in a ReAct loop execution (Thought → Action → Observation)."""
 
     __tablename__ = "automation_agent_run_steps"
@@ -296,7 +296,7 @@ class AgentRunStep(Base, TenantMixin):
     )
 
 
-class AgentSubtask(Base, TenantMixin):
+class AgentSubtask(Base, TenantMixin, OwnedMixin):
     """A subtask delegated from one agent to another for multi-agent orchestration."""
 
     __tablename__ = "agent_subtasks"
@@ -333,7 +333,7 @@ class AgentSubtask(Base, TenantMixin):
     )
 
 
-class SkillDefinitionDB(Base, TenantMixin):
+class SkillDefinitionDB(Base, TenantMixin, OwnedMixin):
     """A skill definition persisted per tenant.
 
     Skills are orchestration metadata, NOT a permission source. They reference