fix(wcd): create sticker assets when reused content is a reference

backend/service/app.py

@@ -1342,7 +1342,7 @@ def _find_asset_by_sha256(digest: str) -> dict | None:
 def _register_import_asset(name: str, content: bytes, mime: str) -> dict:
     digest = hashlib.sha256(content).hexdigest()
     existing = _find_asset_by_sha256(digest)
-    if existing:
+    if existing and existing.get("type") == "sticker":
         return existing
 
     asset_id = f"asset_{uuid.uuid4().hex}"

backend/tests/test_wcd_import.py

@@ -90,6 +90,31 @@ def test_stale_sha256_meta_does_not_reuse_mismatched_file(isolated_asset_store):
     assert len(asset_dirs(isolated_asset_store)) == 2
 
 
+def test_reference_with_same_content_creates_sticker_asset(isolated_asset_store):
+    content = SVG.encode()
+    existing_id = "asset_reference00000000000000000000000"
+    existing_dir = isolated_asset_store / existing_id[:2] / existing_id
+    existing_dir.mkdir(parents=True)
+    (existing_dir / "asset.svg").write_bytes(content)
+    (existing_dir / "meta.json").write_text(
+        json.dumps(
+            {
+                "asset_id": existing_id,
+                "name": "old",
+                "type": "reference",
+                "mime_type": "image/svg+xml",
+                "sha256": hashlib.sha256(content).hexdigest(),
+            }
+        )
+    )
+
+    imported = app._register_import_asset("new", content, "image/svg+xml")
+
+    assert imported["asset_id"] != existing_id
+    assert imported["type"] == "sticker"
+    assert len(asset_dirs(isolated_asset_store)) == 2
+
+
 def test_wcd_production_uses_real_asset_ids(tmp_path, isolated_asset_store, monkeypatch):
     manifest = {
         "format": "wordcloud-canvas",