fix(rmbg): 将 on_event 迁移到 lifespan 事件处理器以消除弃用警告

apps/rmbg/app.py

@@ -1,29 +1,30 @@
+from contextlib import asynccontextmanager
 from fastapi import FastAPI
 from settings import settings
 from api import router, service
 
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    """应用生命周期管理"""
+    # 启动时初始化
+    if settings.enable_queue_batch:
+        await service._start_queue_processor()
+    yield
+    # 关闭时清理资源
+    await service.cleanup()
+
+
 app = FastAPI(
     title="Remove Background",
     description="图片去背景",
-    version="1.0.0"
+    version="1.0.0",
+    lifespan=lifespan
 )
 
 # 注册路由
 app.include_router(router)
 
-
-@app.on_event("startup")
-async def startup_event():
-    """应用启动时初始化队列批处理机制"""
-    if settings.enable_queue_batch:
-        await service._start_queue_processor()
-
-
-@app.on_event("shutdown")
-async def shutdown_event():
-    """应用关闭时清理资源"""
-    await service.cleanup()
-
 if __name__ == "__main__":
     import uvicorn
     uvicorn.run(