feat(example-images): add force parameter to retry failed downloads

When force=true is passed via API, models in failed_models set are
re-downloaded instead of being skipped. On successful download, model is
removed from failed_models set.

This provides a manual batch repair mechanism for users when CivitAI
media server is temporarily down and causes empty folders.

Changes:
- Backend: Add force parameter to start_download(), _download_all_example_images(), _process_model()
- Backend: Skip failed_models check when force=true
- Backend: Remove model from failed_models on successful force retry
- Frontend: GlobalContextMenu now calls API with force=true directly
- Tests: Update mock to accept force parameter

static/js/components/ContextMenu/GlobalContextMenu.js

@@ -75,13 +75,6 @@ export class GlobalContextMenu extends BaseContextMenu {
     }
 
     async downloadExampleImages(menuItem) {
-        const exampleImagesManager = window.exampleImagesManager;
-
-        if (!exampleImagesManager) {
-            showToast('globalContextMenu.downloadExampleImages.unavailable', {}, 'error');
-            return;
-        }
-
         const downloadPath = state?.global?.settings?.example_images_path;
         if (!downloadPath) {
             showToast('globalContextMenu.downloadExampleImages.missingPath', {}, 'warning');
@@ -91,7 +84,48 @@ export class GlobalContextMenu extends BaseContextMenu {
         menuItem?.classList.add('disabled');
 
         try {
-            await exampleImagesManager.handleDownloadButton();
+            const optimize = state.global.settings.optimize_example_images;
+
+            const response = await fetch('/api/lm/download-example-images', {
+                method: 'POST',
+                headers: {
+                    'Content-Type': 'application/json'
+                },
+                body: JSON.stringify({
+                    force: true,
+                    optimize,
+                    model_types: ['lora', 'checkpoint', 'embedding']
+                })
+            });
+
+            const data = await response.json();
+
+            if (data.success) {
+                showToast('toast.exampleImages.downloadStarted', {}, 'success');
+
+                const exampleImagesManager = window.exampleImagesManager;
+                if (exampleImagesManager) {
+                    exampleImagesManager.isDownloading = true;
+                    exampleImagesManager.isPaused = false;
+                    exampleImagesManager.isStopping = false;
+                    exampleImagesManager.hasShownCompletionToast = false;
+                    exampleImagesManager.startTime = new Date();
+                    exampleImagesManager.updateUI(data.status);
+                    exampleImagesManager.showProgressPanel();
+                    exampleImagesManager.startProgressUpdates();
+                    exampleImagesManager.updateDownloadButtonText();
+
+                    const stopButton = document.getElementById('stopExampleDownloadBtn');
+                    if (stopButton) {
+                        stopButton.disabled = false;
+                    }
+                }
+            } else {
+                showToast('toast.exampleImages.downloadStartFailed', { error: data.error }, 'error');
+            }
+        } catch (error) {
+            console.error('Failed to trigger example images download:', error);
+            showToast('toast.exampleImages.downloadStartFailed', {}, 'error');
         } finally {
             menuItem?.classList.remove('disabled');
         }

tests/utils/test_example_images_download_manager_unit.py

@@ -29,12 +29,14 @@ def restore_settings() -> None:
         manager.settings.update(original)
 
 
-async def test_start_download_requires_configured_path(monkeypatch: pytest.MonkeyPatch) -> None:
+async def test_start_download_requires_configured_path(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
     manager = download_module.DownloadManager(ws_manager=RecordingWebSocketManager())
 
     # Ensure example_images_path is not configured
     settings_manager = get_settings_manager()
-    settings_manager.settings.pop('example_images_path', None)
+    settings_manager.settings.pop("example_images_path", None)
 
     with pytest.raises(download_module.DownloadConfigurationError) as exc_info:
         await manager.start_download({})
@@ -46,7 +48,9 @@ async def test_start_download_requires_configured_path(monkeypatch: pytest.Monke
     assert "skipping auto download" in result["message"]
 
 
-async def test_start_download_bootstraps_progress_and_task(monkeypatch: pytest.MonkeyPatch, tmp_path) -> None:
+async def test_start_download_bootstraps_progress_and_task(
+    monkeypatch: pytest.MonkeyPatch, tmp_path
+) -> None:
     settings_manager = get_settings_manager()
     settings_manager.settings["example_images_path"] = str(tmp_path)
     settings_manager.settings["libraries"] = {"default": {}}
@@ -58,7 +62,9 @@ async def test_start_download_bootstraps_progress_and_task(monkeypatch: pytest.M
     started = asyncio.Event()
     release = asyncio.Event()
 
-    async def fake_download(self, output_dir, optimize, model_types, delay, library_name):
+    async def fake_download(
+        self, output_dir, optimize, model_types, delay, library_name, force=False
+    ):
         started.set()
         await release.wait()
         async with self._state_lock:
@@ -129,7 +135,9 @@ async def test_pause_and_resume_flow(monkeypatch: pytest.MonkeyPatch, tmp_path)
     await asyncio.wait_for(task, timeout=1)
 
 
-async def test_stop_download_transitions_to_stopped(monkeypatch: pytest.MonkeyPatch, tmp_path) -> None:
+async def test_stop_download_transitions_to_stopped(
+    monkeypatch: pytest.MonkeyPatch, tmp_path
+) -> None:
     settings_manager = get_settings_manager()
     settings_manager.settings["example_images_path"] = str(tmp_path)
     settings_manager.settings["libraries"] = {"default": {}}
@@ -145,13 +153,13 @@ async def test_stop_download_transitions_to_stopped(monkeypatch: pytest.MonkeyPa
         started.set()
         await release.wait()
         async with self._state_lock:
-            if self._stop_requested and self._progress['status'] == 'stopping':
-                self._progress['status'] = 'stopped'
+            if self._stop_requested and self._progress["status"] == "stopping":
+                self._progress["status"] = "stopped"
             else:
-                self._progress['status'] = 'completed'
-            self._progress['end_time'] = time.time()
+                self._progress["status"] = "completed"
+            self._progress["end_time"] = time.time()
             self._stop_requested = False
-        await self._broadcast_progress(status=self._progress['status'])
+        await self._broadcast_progress(status=self._progress["status"])
         async with self._state_lock:
             self._is_downloading = False
             self._download_task = None
@@ -182,7 +190,9 @@ async def test_stop_download_transitions_to_stopped(monkeypatch: pytest.MonkeyPa
     assert "stopped" in statuses
 
 
-async def test_pause_or_resume_without_running_download(monkeypatch: pytest.MonkeyPatch) -> None:
+async def test_pause_or_resume_without_running_download(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
     manager = download_module.DownloadManager(ws_manager=RecordingWebSocketManager())
 
     with pytest.raises(download_module.DownloadNotRunningError):