Phase 1A: Remove company routes/services/models/schemas, unify to Contact

- Removed: app/routes/companies.py, app/services/company_service.py, app/models/company.py, app/schemas/company.py
- Updated: main.py, routes/__init__.py, models/__init__.py (removed company imports)
- Updated: action_mapper.py (company intents → contact intents, /api/v1/companies → /api/v1/contacts)
- Updated: workflows/engine.py (company.created → contact.created)
- Updated: worker.py (removed index_company)
- Updated: roles.py, permission_registry.py, permissions.py, deps.py (companies: → contacts:)
- Updated: permission_registry.py CORE_FIELD_DEFINITIONS (old field names → unified contact fields)
- Updated: address model/schema/service (entity_type company → contact only)
- Updated: ai_copilot_service.py (_exec_companies removed, _exec_contacts extended)
- Updated: ai_proactive services/jobs/context_tools (Company → Contact, company_contacts → contact_persons)
- Updated: unified_search jobs.py (removed index_company), query_understanding.py
- Updated: calendar/models.py, addresses.py docstrings
- Updated: conftest.py (Company → Contact, removed companies/company_contacts from TRUNCATE)
- Updated: test_unified_search.py (index_company → index_contact)

app/plugins/builtins/ai_proactive/context_tools.py

@@ -263,7 +263,7 @@ def register_context_tools(registry) -> None:
         parameters={
             "type": "object",
             "properties": {
-                "entity_type": {"type": "string", "description": "contact, company, mail, file, event"},
+                "entity_type": {"type": "string", "description": "contact, mail, file, event"},
                 "entity_id": {"type": "string", "description": "UUID der Entity"},
                 "limit": {"type": "integer", "default": 5, "description": "Max results per type"},
             },
@@ -300,7 +300,7 @@ def register_context_tools(registry) -> None:
         parameters={
             "type": "object",
             "properties": {
-                "entity_type": {"type": "string", "description": "contact or company"},
+                "entity_type": {"type": "string", "description": "contact"},
                 "entity_id": {"type": "string", "description": "UUID der Entity"},
             },
             "required": ["entity_type", "entity_id"],