feat: update CSV import to support multi-language translations

- Add language parameter to import endpoints and background tasks
- Extract translation fields (title, description, short_description)
- Create/update MarketplaceProductTranslation records during import
- Add MarketplaceProductTranslationSchema for API responses
- Map product_type column to product_type_raw to avoid enum conflict
- Parse prices to numeric format (price_numeric, sale_price_numeric)
- Update marketplace product service for translation-based lookups
- Update CSV export to retrieve titles from translations

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/tasks/background_tasks.py

@@ -1,4 +1,6 @@
 # app/tasks/background_tasks.py
+"""Background tasks for marketplace imports."""
+
 import logging
 from datetime import UTC, datetime
 
@@ -14,10 +16,20 @@ async def process_marketplace_import(
     job_id: int,
     url: str,
     marketplace: str,
-    vendor_id: int,  # FIXED: Changed from vendor_name to vendor_id
+    vendor_id: int,
     batch_size: int = 1000,
+    language: str = "en",
 ):
-    """Background task to process marketplace CSV import."""
+    """Background task to process marketplace CSV import.
+
+    Args:
+        job_id: ID of the MarketplaceImportJob record
+        url: URL to the CSV file
+        marketplace: Name of the marketplace (e.g., 'Letzshop')
+        vendor_id: ID of the vendor
+        batch_size: Number of rows to process per batch
+        language: Language code for translations (default: 'en')
+    """
     db = SessionLocal()
     csv_processor = CSVProcessor()
     job = None
@@ -50,16 +62,17 @@ async def process_marketplace_import(
 
         logger.info(
             f"Processing import: Job {job_id}, Marketplace: {marketplace}, "
-            f"Vendor: {vendor.name} ({vendor.vendor_code})"
+            f"Vendor: {vendor.name} ({vendor.vendor_code}), Language: {language}"
         )
 
-        # Process CSV with vendor_id
+        # Process CSV with vendor name and language
         result = await csv_processor.process_marketplace_csv_from_url(
-            url,
-            marketplace,
-            vendor_id,  # FIXED: Pass vendor_id instead of vendor_name
-            batch_size,
-            db,
+            url=url,
+            marketplace=marketplace,
+            vendor_name=vendor.name,  # Pass vendor name to CSV processor
+            batch_size=batch_size,
+            db=db,
+            language=language,  # Pass language for translations
         )
 
         # Update job with results