fix(uploads): ignore mention references in new upload detection

backend/packages/harness/deerflow/agents/middlewares/uploads_middleware.py

@@ -168,6 +168,9 @@ class UploadsMiddleware(AgentMiddleware[UploadsMiddlewareState]):
         for f in kwargs_files:
             if not isinstance(f, dict):
                 continue
+            # Mention references are context pointers, not newly uploaded files.
+            if f.get("ref_kind") == "mention":
+                continue
             filename = f.get("filename") or ""
             if not filename or Path(filename).name != filename:
                 continue

backend/tests/test_uploads_middleware_core_logic.py

@@ -143,6 +143,45 @@ class TestFilesFromKwargs:
         assert result is not None
         assert result[0]["size"] == 0
 
+    def test_skips_mention_reference_entries(self, tmp_path):
+        mw = _middleware(tmp_path)
+        msg = _human(
+            "hi",
+            files=[
+                {
+                    "filename": "mention.jpg",
+                    "size": 123,
+                    "path": "/mnt/user-data/uploads/mention.jpg",
+                    "ref_kind": "mention",
+                    "ref_source": "upload",
+                }
+            ],
+        )
+        assert mw._files_from_kwargs(msg) is None
+
+    def test_mixed_list_keeps_uploads_but_skips_mentions(self, tmp_path):
+        mw = _middleware(tmp_path)
+        msg = _human(
+            "hi",
+            files=[
+                {
+                    "filename": "uploaded.txt",
+                    "size": 10,
+                    "path": "/mnt/user-data/uploads/uploaded.txt",
+                },
+                {
+                    "filename": "mentioned.txt",
+                    "size": 8,
+                    "path": "/mnt/user-data/uploads/mentioned.txt",
+                    "ref_kind": "mention",
+                    "ref_source": "upload",
+                },
+            ],
+        )
+        result = mw._files_from_kwargs(msg)
+        assert result is not None
+        assert [f["filename"] for f in result] == ["uploaded.txt"]
+
 
 # ---------------------------------------------------------------------------
 # _create_files_message