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/order_service.py

@@ -11,15 +11,17 @@ This module provides:
 import logging
 import random
 import string
-from datetime import datetime, timezone
-from typing import List, Optional, Tuple
+from datetime import UTC, datetime
 
-from sqlalchemy import and_, or_
+from sqlalchemy import and_
 from sqlalchemy.orm import Session
 
-from app.exceptions import (CustomerNotFoundException,
-                            InsufficientInventoryException,
-                            OrderNotFoundException, ValidationException)
+from app.exceptions import (
+    CustomerNotFoundException,
+    InsufficientInventoryException,
+    OrderNotFoundException,
+    ValidationException,
+)
 from models.database.customer import Customer, CustomerAddress
 from models.database.order import Order, OrderItem
 from models.database.product import Product
@@ -38,7 +40,7 @@ class OrderService:
         Format: ORD-{VENDOR_ID}-{TIMESTAMP}-{RANDOM}
         Example: ORD-1-20250110-A1B2C3
         """
-        timestamp = datetime.now(timezone.utc).strftime("%Y%m%d")
+        timestamp = datetime.now(UTC).strftime("%Y%m%d")
         random_suffix = "".join(
             random.choices(string.ascii_uppercase + string.digits, k=6)
         )
@@ -266,9 +268,9 @@ class OrderService:
         vendor_id: int,
         skip: int = 0,
         limit: int = 100,
-        status: Optional[str] = None,
-        customer_id: Optional[int] = None,
-    ) -> Tuple[List[Order], int]:
+        status: str | None = None,
+        customer_id: int | None = None,
+    ) -> tuple[list[Order], int]:
         """
         Get orders for vendor with filtering.
 
@@ -306,7 +308,7 @@ class OrderService:
         customer_id: int,
         skip: int = 0,
         limit: int = 100,
-    ) -> Tuple[List[Order], int]:
+    ) -> tuple[list[Order], int]:
         """Get orders for a specific customer."""
         return self.get_vendor_orders(
             db=db, vendor_id=vendor_id, skip=skip, limit=limit, customer_id=customer_id
@@ -335,7 +337,7 @@ class OrderService:
                 order.status = order_update.status
 
                 # Update timestamp based on status
-                now = datetime.now(timezone.utc)
+                now = datetime.now(UTC)
                 if order_update.status == "shipped" and not order.shipped_at:
                     order.shipped_at = now
                 elif order_update.status == "delivered" and not order.delivered_at:
@@ -351,7 +353,7 @@ class OrderService:
             if order_update.internal_notes:
                 order.internal_notes = order_update.internal_notes
 
-            order.updated_at = datetime.now(timezone.utc)
+            order.updated_at = datetime.now(UTC)
             db.commit()
             db.refresh(order)