feat: enhance Letzshop jobs and order management

- Add job cancellation and retry functionality
- Improve jobs table with better status display
- Add background task improvements
- Update Letzshop order service
- Update documentation

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

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

app/services/letzshop/order_service.py

@@ -619,6 +619,11 @@ class LetzshopOrderService:
         """
         jobs = []
 
+        # Fetch vendor info once for all jobs
+        vendor = self.get_vendor(vendor_id)
+        vendor_name = vendor.name if vendor else None
+        vendor_code = vendor.vendor_code if vendor else None
+
         # Historical order imports from letzshop_historical_import_jobs
         if job_type in (None, "historical_import"):
             hist_query = self.db.query(LetzshopHistoricalImportJob).filter(
@@ -646,6 +651,9 @@ class LetzshopOrderService:
                         "records_succeeded": (job.orders_imported or 0)
                         + (job.orders_updated or 0),
                         "records_failed": job.orders_skipped or 0,
+                        "vendor_id": vendor_id,
+                        "vendor_name": vendor_name,
+                        "vendor_code": vendor_code,
                         "current_phase": job.current_phase,
                         "error_message": job.error_message,
                     }
@@ -679,6 +687,9 @@ class LetzshopOrderService:
                         "records_succeeded": (job.imported_count or 0)
                         + (job.updated_count or 0),
                         "records_failed": job.error_count or 0,
+                        "vendor_id": vendor_id,
+                        "vendor_name": vendor_name,
+                        "vendor_code": vendor_code,
                     }
                 )
 
@@ -705,6 +716,9 @@ class LetzshopOrderService:
                         "records_processed": log.records_processed or 0,
                         "records_succeeded": log.records_succeeded or 0,
                         "records_failed": log.records_failed or 0,
+                        "vendor_id": vendor_id,
+                        "vendor_name": vendor_name,
+                        "vendor_code": vendor_code,
                         "error_details": log.error_details,
                     }
                 )
@@ -734,6 +748,9 @@ class LetzshopOrderService:
                         "records_processed": log.records_processed or 0,
                         "records_succeeded": log.records_succeeded or 0,
                         "records_failed": log.records_failed or 0,
+                        "vendor_id": vendor_id,
+                        "vendor_name": vendor_name,
+                        "vendor_code": vendor_code,
                         "error_details": log.error_details,  # Include export file details
                     }
                 )