refactor: modernize code quality tooling with Ruff

- Replace black, isort, and flake8 with Ruff (all-in-one linter and formatter)
- Add comprehensive pyproject.toml configuration
- Simplify Makefile code quality targets
- Configure exclusions for venv/.venv in pyproject.toml
- Auto-fix 1,359 linting issues across codebase

Benefits:
- Much faster builds (Ruff is written in Rust)
- Single tool replaces multiple tools
- More comprehensive rule set (UP, B, C4, SIM, PIE, RET, Q)
- All configuration centralized in pyproject.toml
- Better import sorting and formatting consistency

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

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

app/services/vendor_service.py

@@ -10,18 +10,20 @@ This module provides classes and functions for:
 """
 
 import logging
-from typing import List, Optional, Tuple
 
 from sqlalchemy import func
 from sqlalchemy.orm import Session
 
-from app.exceptions import (InvalidVendorDataException,
-                            MarketplaceProductNotFoundException,
-                            MaxVendorsReachedException,
-                            ProductAlreadyExistsException,
-                            UnauthorizedVendorAccessException,
-                            ValidationException, VendorAlreadyExistsException,
-                            VendorNotFoundException)
+from app.exceptions import (
+    InvalidVendorDataException,
+    MarketplaceProductNotFoundException,
+    MaxVendorsReachedException,
+    ProductAlreadyExistsException,
+    UnauthorizedVendorAccessException,
+    ValidationException,
+    VendorAlreadyExistsException,
+    VendorNotFoundException,
+)
 from models.database.marketplace_product import MarketplaceProduct
 from models.database.product import Product
 from models.database.user import User
@@ -108,7 +110,7 @@ class VendorService:
         limit: int = 100,
         active_only: bool = True,
         verified_only: bool = False,
-    ) -> Tuple[List[Vendor], int]:
+    ) -> tuple[list[Vendor], int]:
         """
         Get vendors with filtering.
 
@@ -257,7 +259,7 @@ class VendorService:
         limit: int = 100,
         active_only: bool = True,
         featured_only: bool = False,
-    ) -> Tuple[List[Product], int]:
+    ) -> tuple[list[Product], int]:
         """
         Get products in vendor catalog with filtering.