fix(deploy): serialize model migration and pin nginx

backend/app/core/database.py

@@ -66,6 +66,8 @@ async def init_db():
             PendingReplyTask, TokenStat, AIModelConfig, SystemConfig, LoginLog
         )
         async with engine.begin() as conn:
+            await conn.execute(text("SELECT GET_LOCK('ai_model_usage_scope_migration', 30)"))
+            try:
                 result = await conn.execute(text(
                     "SELECT COUNT(*) FROM information_schema.COLUMNS "
                     "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'ai_model_configs' "
@@ -77,6 +79,8 @@ async def init_db():
                         "VARCHAR(16) NOT NULL DEFAULT 'general' AFTER provider"
                     ))
                     logger.info("AI模型配置表已增加 usage_scope 字段")
+            finally:
+                await conn.execute(text("SELECT RELEASE_LOCK('ai_model_usage_scope_migration')"))
         logger.info("✅ 数据库模型注册成功")
         logger.info("✅ 数据库初始化完成")
 

frontend/Dockerfile

@@ -6,7 +6,8 @@ RUN npm install
 COPY . .
 RUN npm run build
 
-FROM nginx:alpine
+# Nginx 1.31 uses syscalls that are blocked by the test server's legacy kernel.
+FROM nginx:1.28.3-alpine
 COPY --from=build /app/dist /usr/share/nginx/html
 COPY nginx.conf /etc/nginx/conf.d/default.conf
 EXPOSE 80