style: apply black and isort formatting across entire codebase

- Standardize quote style (single to double quotes)
- Reorder and group imports alphabetically
- Fix line breaks and indentation for consistency
- Apply PEP 8 formatting standards

Also updated Makefile to exclude both venv and .venv from code quality checks.

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

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

tasks/analytics_tasks.py

@@ -1 +1 @@
-# Analytics and reporting tasks 
+# Analytics and reporting tasks

tasks/backup_tasks.py

@@ -1 +1 @@
-# Backup and recovery tasks 
+# Backup and recovery tasks

tasks/cleanup_tasks.py

@@ -1 +1 @@
-# Data cleanup and maintenance tasks 
+# Data cleanup and maintenance tasks

tasks/email_tasks.py

@@ -1 +1 @@
-# Email sending tasks 
+# Email sending tasks

tasks/marketplace_import.py

@@ -1,12 +1,12 @@
-# Marketplace CSV import tasks 
+# Marketplace CSV import tasks
 # app/tasks/background_tasks.py
 import logging
 from datetime import datetime, timezone
 
 from app.core.database import SessionLocal
+from app.utils.csv_processor import CSVProcessor
 from models.database.marketplace_import_job import MarketplaceImportJob
 from models.database.vendor import Vendor
-from app.utils.csv_processor import CSVProcessor
 
 logger = logging.getLogger(__name__)
 
@@ -16,7 +16,7 @@ async def process_marketplace_import(
     url: str,
     marketplace: str,
     vendor_id: int,  # FIXED: Changed from vendor_name to vendor_id
-    batch_size: int = 1000
+    batch_size: int = 1000,
 ):
     """Background task to process marketplace CSV import."""
     db = SessionLocal()
@@ -60,7 +60,7 @@ async def process_marketplace_import(
             marketplace,
             vendor_id,  # FIXED: Pass vendor_id instead of vendor_name
             batch_size,
-            db
+            db,
         )
 
         # Update job with results

tasks/media_processing.py

@@ -1 +1 @@
-# Image processing and optimization tasks 
+# Image processing and optimization tasks

tasks/search_indexing.py

@@ -1 +1 @@
-# Search index maintenance tasks 
+# Search index maintenance tasks

tasks/task_manager.py

@@ -1 +1 @@
-# Celery configuration and task management 
+# Celery configuration and task management