feat: 운영 안정성과 세션 음성 경험 개선

infra/db/init/05_runtime_auth.sql

@@ -70,10 +70,14 @@ CREATE TABLE IF NOT EXISTS app.admin_engine_config (
   engine_mode TEXT NOT NULL,
   engine_url TEXT NOT NULL,
   model TEXT NOT NULL,
+  reasoning_effort TEXT,
   updated_by TEXT,
   updated_at TIMESTAMPTZ
 );
 
+ALTER TABLE app.admin_engine_config
+  ADD COLUMN IF NOT EXISTS reasoning_effort TEXT;
+
 CREATE TABLE IF NOT EXISTS app.admin_health_event (
   id BIGSERIAL PRIMARY KEY,
   observed_at TIMESTAMPTZ NOT NULL DEFAULT now(),