test: fold the last Windows path and label assumptions

Second pass over the informational Windows job (91 failures -> 11 -> 0):

* `_identity`/`_fold` now wrap the assertions my first sweep skipped: the
  parenthesised and multi-line ones, and the ones whose token list was
  incomplete (`base_models_roots`, `embeddings_roots`).
* The reconciler's `current_name` and `active_roots` carry the drive-prefixed
  label on Windows ("C: loras"), so the last direct comparison goes through
  `_root_label_names` too.
* `open_settings_location` reveals the settings *file* with
  `explorer /select,` on Windows instead of opening the containing folder, so
  that test asserts the platform's call instead of the POSIX one.
* Three more expectations are written in the business form the code returns
  (metadata payload, extracted download paths, hydrated preview URL).

tests/routes/test_misc_routes.py

@@ -788,7 +788,11 @@ async def test_open_settings_location_with_display_opens_folder(tmp_path, monkey
 
     assert response.status == 200
     assert payload["success"] is True
-    assert calls == [[_expected_opener(), str(settings_file.parent)]]
+    if os.name == "nt":
+        # explorer reveals the file itself, there is no "open the folder" call.
+        assert calls == [["explorer", "/select,", str(settings_file)]]
+    else:
+        assert calls == [[_expected_opener(), str(settings_file.parent)]]
 
 
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