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>

models/schema/marketplace_import_job.py

@@ -1,5 +1,6 @@
 from datetime import datetime
 from typing import Optional
+
 from pydantic import BaseModel, ConfigDict, Field, field_validator
 
 
@@ -8,9 +9,12 @@ class MarketplaceImportJobRequest(BaseModel):
 
     Note: vendor_id is injected by middleware, not from request body.
     """
+
     source_url: str = Field(..., description="URL to CSV file from marketplace")
     marketplace: str = Field(default="Letzshop", description="Marketplace name")
-    batch_size: Optional[int] = Field(1000, description="Processing batch size", ge=100, le=10000)
+    batch_size: Optional[int] = Field(
+        1000, description="Processing batch size", ge=100, le=10000
+    )
 
     @field_validator("source_url")
     @classmethod
@@ -28,6 +32,7 @@ class MarketplaceImportJobRequest(BaseModel):
 
 class MarketplaceImportJobResponse(BaseModel):
     """Response schema for marketplace import job."""
+
     model_config = ConfigDict(from_attributes=True)
 
     job_id: int
@@ -55,6 +60,7 @@ class MarketplaceImportJobResponse(BaseModel):
 
 class MarketplaceImportJobListResponse(BaseModel):
     """Response schema for list of import jobs."""
+
     jobs: list[MarketplaceImportJobResponse]
     total: int
     skip: int
@@ -63,6 +69,7 @@ class MarketplaceImportJobListResponse(BaseModel):
 
 class MarketplaceImportJobStatusUpdate(BaseModel):
     """Schema for updating import job status (internal use)."""
+
     status: str
     imported_count: Optional[int] = None
     updated_count: Optional[int] = None