feat: implement batch import recipe functionality (frontend + backend fixes)

Backend fixes:
- Add missing API route for /api/lm/recipes/batch-import/progress (GET)
- Add missing API route for /api/lm/recipes/batch-import/directory (POST)
- Add missing API route for /api/lm/recipes/browse-directory (POST)
- Register WebSocket endpoint for batch import progress
- Fix skip_no_metadata default value (True -> False) to allow no-LoRA imports
- Add items array to BatchImportProgress.to_dict() for detailed results

Frontend implementation:
- Create BatchImportManager.js with complete batch import workflow
- Add directory browser UI for selecting folders
- Add batch import modal with URL list and directory input modes
- Implement real-time progress tracking (WebSocket + HTTP polling)
- Add results summary with success/failed/skipped statistics
- Add expandable details view showing individual item status
- Auto-refresh recipe list after import completion

UI improvements:
- Add spinner animation for importing status
- Simplify results summary UI to match progress stats styling
- Fix current item text alignment
- Fix dark theme styling for directory browser button
- Fix batch import button styling consistency

Translations:
- Add batch import related i18n keys to all locale files
- Run sync_translation_keys.py to sync all translations

Fixes:
- Batch import now allows images without LoRAs (matches single import behavior)
- Progress endpoint now returns complete items array with status details
- Results view correctly displays skipped items with error messages

locales/en.json

@@ -733,33 +733,55 @@
         "batchImport": {
             "title": "Batch Import Recipes",
             "action": "Batch Import",
-            "urlsMode": "URLs / Paths",
-            "directoryMode": "Directory",
-            "urlsDescription": "Enter image URLs or local file paths (one per line). Each will be imported as a recipe.",
+            "urlList": "URL List",
+            "directory": "Directory",
+            "urlDescription": "Enter image URLs or local file paths (one per line). Each will be imported as a recipe.",
+            "directoryDescription": "Enter a directory path to import all images from that folder.",
             "urlsLabel": "Image URLs or Local Paths",
             "urlsPlaceholder": "https://civitai.com/images/...\nhttps://civitai.com/images/...\nC:/path/to/image.png\n...",
-            "directoryDescription": "Enter a directory path to import all images from that folder.",
-            "directoryLabel": "Directory Path",
+            "urlsHint": "Enter one URL or path per line",
+            "directoryPath": "Directory Path",
             "directoryPlaceholder": "/path/to/images/folder",
+            "browse": "Browse",
+            "recursive": "Include subdirectories",
             "tagsOptional": "Tags (optional, applied to all recipes)",
-            "addTagPlaceholder": "Add a tag",
-            "addTag": "Add",
-            "noTags": "No tags added",
+            "tagsPlaceholder": "Enter tags separated by commas",
+            "tagsHint": "Tags will be added to all imported recipes",
             "skipNoMetadata": "Skip images without metadata",
             "skipNoMetadataHelp": "Images without LoRA metadata will be skipped automatically.",
+            "start": "Start Import",
             "startImport": "Start Import",
-            "importing": "Importing Recipes...",
+            "importing": "Importing...",
             "progress": "Progress",
+            "total": "Total",
+            "success": "Success",
+            "failed": "Failed",
+            "skipped": "Skipped",
+            "current": "Current",
             "currentItem": "Current",
             "preparing": "Preparing...",
+            "cancel": "Cancel",
             "cancelImport": "Cancel",
-            "cancelled": "Batch import cancelled",
-            "completed": "Import Completed",
+            "cancelled": "Import cancelled",
+            "completed": "Import completed",
+            "completedWithErrors": "Completed with errors",
             "completedSuccess": "Successfully imported {count} recipe(s)",
             "successCount": "Successful",
             "failedCount": "Failed",
             "skippedCount": "Skipped",
             "totalProcessed": "Total processed",
+            "viewDetails": "View Details",
+            "newImport": "New Import",
+            "manualPathEntry": "Please enter the directory path manually. File browser is not available in this browser.",
+            "batchImportDirectorySelected": "Directory selected: {path}",
+            "batchImportManualEntryRequired": "File browser not available. Please enter the directory path manually.",
+            "backToParent": "Back to parent directory",
+            "folders": "Folders",
+            "folderCount": "{count} folders",
+            "imageFiles": "Image Files",
+            "images": "images",
+            "imageCount": "{count} images",
+            "selectFolder": "Select This Folder",
             "errors": {
                 "enterUrls": "Please enter at least one URL or path",
                 "enterDirectory": "Please enter a directory path",
@@ -1474,7 +1496,14 @@
             "recipeSaveFailed": "Failed to save recipe: {error}",
             "importFailed": "Import failed: {message}",
             "folderTreeFailed": "Failed to load folder tree",
-            "folderTreeError": "Error loading folder tree"
+            "folderTreeError": "Error loading folder tree",
+            "batchImportFailed": "Failed to start batch import: {message}",
+            "batchImportCancelling": "Cancelling batch import...",
+            "batchImportCancelFailed": "Failed to cancel batch import: {message}",
+            "batchImportNoUrls": "Please enter at least one URL or file path",
+            "batchImportNoDirectory": "Please enter a directory path",
+            "batchImportBrowseFailed": "Failed to browse directory: {message}",
+            "batchImportDirectorySelected": "Directory selected: {path}"
         },
         "models": {
             "noModelsSelected": "No models selected",