feat: 운영 안정성과 세션 음성 경험 개선

apps/api/app/db.py

@@ -148,7 +148,12 @@ async def healthcheck() -> bool:
                   to_regclass('app.app_user') IS NOT NULL AS has_user,
                   to_regclass('app.auth_session') IS NOT NULL AS has_auth_session,
                   to_regclass('app.user_preferences') IS NOT NULL AS has_preferences,
-                  to_regclass('app.admin_engine_config') IS NOT NULL AS has_engine_config,
+                  EXISTS (
+                    SELECT 1 FROM information_schema.columns
+                    WHERE table_schema = 'app'
+                      AND table_name = 'admin_engine_config'
+                      AND column_name = 'reasoning_effort'
+                  ) AS has_engine_config,
                   to_regclass('app.admin_health_event') IS NOT NULL AS has_admin_health_event,
                   to_regclass('app.admin_health_daily_rollup') IS NOT NULL AS has_admin_health_daily_rollup,
                   to_regclass('app.support_ticket') IS NOT NULL AS has_support_ticket,