Cover the unhashed temp asset in the reconciliation tests

The existing temp tests all registered hashed assets, so they never
exercised the path an unhashed asset takes when its file is gone: the
orphaned rows are removed rather than kept as missing, exactly as under
any other root.

tests-unit/assets_test/test_temp_assets.py

@@ -62,8 +62,17 @@ def _write(directory: Path, name: str) -> str:
     return str(p)
 
 
-def _register(session: Session, file_path: str, ref_id: str, *, mtime_ns: int) -> None:
-    session.add(Asset(id=f"asset-{ref_id}", hash=f"blake3:{ref_id}", size_bytes=100))
+def _register(
+    session: Session,
+    file_path: str,
+    ref_id: str,
+    *,
+    mtime_ns: int,
+    asset_hash: str | None = "",
+) -> None:
+    if asset_hash == "":
+        asset_hash = f"blake3:{ref_id}"
+    session.add(Asset(id=f"asset-{ref_id}", hash=asset_hash, size_bytes=100))
     session.flush()
     session.add(
         AssetReference(
@@ -139,6 +148,24 @@ def test_temp_sync_marks_deleted_file_missing(session, comfy_dirs):
     )
 
 
+def test_temp_sync_drops_unhashed_asset_whose_file_is_gone(session, comfy_dirs):
+    temp_file = _write(comfy_dirs["temp"], "preview.png")
+    _register(session, temp_file, "temp-ref", mtime_ns=_mtime(temp_file), asset_hash=None)
+    session.commit()
+    os.remove(temp_file)
+
+    sync_prefixes_with_filesystem(session, get_temp_prefixes())
+    session.commit()
+
+    session.expire_all()
+    assert session.get(AssetReference, "temp-ref") is None, (
+        "an unhashed asset with no surviving reference is retired, not kept as missing"
+    )
+    assert session.get(Asset, "asset-temp-ref") is None, (
+        "the orphaned asset row goes with its last reference"
+    )
+
+
 def test_temp_sync_keeps_live_file(session, comfy_dirs):
     temp_file = _write(comfy_dirs["temp"], "preview.png")
     _register(session, temp_file, "temp-ref", mtime_ns=_mtime(temp_file))