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/api/v1/shop/cart.py

@@ -14,9 +14,13 @@ from sqlalchemy.orm import Session
 
 from app.core.database import get_db
 from app.services.cart_service import cart_service
-from models.schema.cart import (AddToCartRequest, CartOperationResponse,
-                                CartResponse, ClearCartResponse,
-                                UpdateCartItemRequest)
+from models.schema.cart import (
+    AddToCartRequest,
+    CartOperationResponse,
+    CartResponse,
+    ClearCartResponse,
+    UpdateCartItemRequest,
+)
 
 router = APIRouter()
 logger = logging.getLogger(__name__)

app/api/v1/shop/content_pages.py

@@ -7,7 +7,6 @@ No authentication required.
 """
 
 import logging
-from typing import List
 
 from fastapi import APIRouter, Depends, HTTPException, Request
 from pydantic import BaseModel
@@ -52,7 +51,7 @@ class ContentPageListItem(BaseModel):
 # ============================================================================
 
 
-@router.get("/navigation", response_model=List[ContentPageListItem])
+@router.get("/navigation", response_model=list[ContentPageListItem])
 def get_navigation_pages(request: Request, db: Session = Depends(get_db)):
     """
     Get list of content pages for navigation (footer/header).

app/api/v1/shop/orders.py

@@ -8,7 +8,6 @@ Requires customer authentication for most operations.
 """
 
 import logging
-from typing import Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Path, Query, Request
 from sqlalchemy.orm import Session
@@ -19,8 +18,12 @@ from app.services.customer_service import customer_service
 from app.services.order_service import order_service
 from models.database.customer import Customer
 from models.database.user import User
-from models.schema.order import (OrderCreate, OrderDetailResponse,
-                                 OrderListResponse, OrderResponse)
+from models.schema.order import (
+    OrderCreate,
+    OrderDetailResponse,
+    OrderListResponse,
+    OrderResponse,
+)
 
 router = APIRouter()
 logger = logging.getLogger(__name__)

app/api/v1/shop/products.py

@@ -8,15 +8,17 @@ No authentication required.
 """
 
 import logging
-from typing import Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Path, Query, Request
 from sqlalchemy.orm import Session
 
 from app.core.database import get_db
 from app.services.product_service import product_service
-from models.schema.product import (ProductDetailResponse, ProductListResponse,
-                                   ProductResponse)
+from models.schema.product import (
+    ProductDetailResponse,
+    ProductListResponse,
+    ProductResponse,
+)
 
 router = APIRouter()
 logger = logging.getLogger(__name__)
@@ -27,8 +29,8 @@ def get_product_catalog(
     request: Request,
     skip: int = Query(0, ge=0),
     limit: int = Query(100, ge=1, le=1000),
-    search: Optional[str] = Query(None, description="Search products by name"),
-    is_featured: Optional[bool] = Query(
+    search: str | None = Query(None, description="Search products by name"),
+    is_featured: bool | None = Query(
         None, description="Filter by featured products"
     ),
     db: Session = Depends(get_db),