Fix model-controller mismatches and routing issues

- ticket: add user_id, priority, category fields; fix _serialize_ticket -> _serialize
- package: fix is_active -> active (Odoo auto-filter), remove invalid entity_id filter
- walkthrough: add sequence field; fix controller to use name/content instead of title/steps
- users: fix encoach_user_type -> encoach_type, encoach_entity_id -> entity_rel_ids.entity_id
- generation: use EncoachGenerationService class instead of nonexistent ORM model,
  fix /api/exam/level/ route conflict (separate GET and POST URLs)

Made-with: Cursor

encoach_api/controllers/users.py

@@ -78,11 +78,11 @@ class UsersController(EncoachMixin, http.Controller):
 
             user_type = kwargs.get('type')
             if user_type:
-                domain.append(('encoach_user_type', '=', user_type))
+                domain.append(('encoach_type', '=', user_type))
 
             entity_id = kwargs.get('entityID')
             if entity_id:
-                domain.append(('encoach_entity_id', '=', int(entity_id)))
+                domain.append(('entity_rel_ids.entity_id', '=', int(entity_id)))
 
             Users = request.env['res.users'].sudo()
             total = Users.search_count(domain)