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>

models/schema/order.py

@@ -4,8 +4,6 @@ Pydantic schema for order operations.
 """
 
 from datetime import datetime
-from decimal import Decimal
-from typing import List, Optional
 
 from pydantic import BaseModel, ConfigDict, Field
 
@@ -30,7 +28,7 @@ class OrderItemResponse(BaseModel):
     order_id: int
     product_id: int
     product_name: str
-    product_sku: Optional[str]
+    product_sku: str | None
     quantity: int
     unit_price: float
     total_price: float
@@ -50,9 +48,9 @@ class OrderAddressCreate(BaseModel):
 
     first_name: str = Field(..., min_length=1, max_length=100)
     last_name: str = Field(..., min_length=1, max_length=100)
-    company: Optional[str] = Field(None, max_length=200)
+    company: str | None = Field(None, max_length=200)
     address_line_1: str = Field(..., min_length=1, max_length=255)
-    address_line_2: Optional[str] = Field(None, max_length=255)
+    address_line_2: str | None = Field(None, max_length=255)
     city: str = Field(..., min_length=1, max_length=100)
     postal_code: str = Field(..., min_length=1, max_length=20)
     country: str = Field(..., min_length=2, max_length=100)
@@ -67,9 +65,9 @@ class OrderAddressResponse(BaseModel):
     address_type: str
     first_name: str
     last_name: str
-    company: Optional[str]
+    company: str | None
     address_line_1: str
-    address_line_2: Optional[str]
+    address_line_2: str | None
     city: str
     postal_code: str
     country: str
@@ -83,29 +81,29 @@ class OrderAddressResponse(BaseModel):
 class OrderCreate(BaseModel):
     """Schema for creating an order."""
 
-    customer_id: Optional[int] = None  # Optional for guest checkout
-    items: List[OrderItemCreate] = Field(..., min_length=1)
+    customer_id: int | None = None  # Optional for guest checkout
+    items: list[OrderItemCreate] = Field(..., min_length=1)
 
     # Addresses
     shipping_address: OrderAddressCreate
-    billing_address: Optional[OrderAddressCreate] = None  # Use shipping if not provided
+    billing_address: OrderAddressCreate | None = None  # Use shipping if not provided
 
     # Optional fields
-    shipping_method: Optional[str] = None
-    customer_notes: Optional[str] = Field(None, max_length=1000)
+    shipping_method: str | None = None
+    customer_notes: str | None = Field(None, max_length=1000)
 
     # Cart/session info
-    session_id: Optional[str] = None
+    session_id: str | None = None
 
 
 class OrderUpdate(BaseModel):
     """Schema for updating order status."""
 
-    status: Optional[str] = Field(
+    status: str | None = Field(
         None, pattern="^(pending|processing|shipped|delivered|cancelled|refunded)$"
     )
-    tracking_number: Optional[str] = None
-    internal_notes: Optional[str] = None
+    tracking_number: str | None = None
+    internal_notes: str | None = None
 
 
 # ============================================================================
@@ -133,26 +131,26 @@ class OrderResponse(BaseModel):
     currency: str
 
     # Shipping
-    shipping_method: Optional[str]
-    tracking_number: Optional[str]
+    shipping_method: str | None
+    tracking_number: str | None
 
     # Notes
-    customer_notes: Optional[str]
-    internal_notes: Optional[str]
+    customer_notes: str | None
+    internal_notes: str | None
 
     # Timestamps
     created_at: datetime
     updated_at: datetime
-    paid_at: Optional[datetime]
-    shipped_at: Optional[datetime]
-    delivered_at: Optional[datetime]
-    cancelled_at: Optional[datetime]
+    paid_at: datetime | None
+    shipped_at: datetime | None
+    delivered_at: datetime | None
+    cancelled_at: datetime | None
 
 
 class OrderDetailResponse(OrderResponse):
     """Schema for detailed order response with items and addresses."""
 
-    items: List[OrderItemResponse]
+    items: list[OrderItemResponse]
     shipping_address: OrderAddressResponse
     billing_address: OrderAddressResponse
 
@@ -160,7 +158,7 @@ class OrderDetailResponse(OrderResponse):
 class OrderListResponse(BaseModel):
     """Schema for paginated order list."""
 
-    orders: List[OrderResponse]
+    orders: list[OrderResponse]
     total: int
     skip: int
     limit: int