feat(server): add PATCH/DELETE /attachment/box mirroring product box ops

Co-Authored-By: Claude <noreply@anthropic.com>

app/main.py

@@ -34,6 +34,7 @@ from app.services.box_service import (
 )
 from app.services.attachment_service import (
     AlreadyOffShelfAttachmentError,
+    AttachmentItemNotFoundError,
     CategoryHasBoxesError,
     CategoryNotFoundError,
     DuplicateAttachmentBoxItemError,
@@ -247,6 +248,16 @@ async def duplicate_attachment_box_handler(
     )
 
 
+@app.exception_handler(AttachmentItemNotFoundError)
+async def attachment_item_not_found_handler(
+    request: Request, exc: AttachmentItemNotFoundError
+):
+    return JSONResponse(
+        status_code=404,
+        content={"error_code": "BOX_ITEM_NOT_FOUND", "message": "指定装箱明细不存在"},
+    )
+
+
 @app.get("/")
 async def root():
     return {"message": "Welcome to CargoTrace API"}