refactor(model_scanner): normalize path comparisons for model roots

fix(example_images_download_manager): re-raise specific exception on download error

refactor(usage_stats): define constants locally to avoid conditional imports

test(example_images_download_manager): update exception handling in download tests

test(example_images_file_manager): differentiate between os.startfile and subprocess.Popen in tests

test(example_images_paths): ensure valid example images root with single-library mode

test(usage_stats): use string literals for metadata payload to avoid conditional imports

tests/utils/test_usage_stats.py

@@ -113,11 +113,12 @@ async def test_usage_stats_background_processor_handles_pending_prompts(tmp_path
     stats, tasks, _ = _prepare_usage_stats(tmp_path, monkeypatch, sleep_override=fast_sleep)
 
     metadata_calls = []
+    # Use string literals directly to avoid dependency on conditional imports
     metadata_payload = {
-        MODELS: {
+        "models": {
             "1": {"type": "checkpoint", "name": "model.ckpt"},
         },
-        LORAS: {
+        "loras": {
             "2": {"lora_list": [{"name": "awesome_lora.safetensors"}]},
         },
     }