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/database/__init__.py

@@ -1,7 +1,13 @@
 # models/database/__init__.py
 """Database models package."""
-from .admin import (AdminAuditLog, AdminNotification, AdminSession,
-                    AdminSetting, PlatformAlert)
+
+from .admin import (
+    AdminAuditLog,
+    AdminNotification,
+    AdminSession,
+    AdminSetting,
+    PlatformAlert,
+)
 from .base import Base
 from .customer import Customer, CustomerAddress
 from .inventory import Inventory

models/database/admin.py

@@ -10,8 +10,16 @@ This module provides models for:
 - Platform alerts (system-wide issues)
 """
 
-from sqlalchemy import (JSON, Boolean, Column, DateTime, ForeignKey, Integer,
-                        String, Text)
+from sqlalchemy import (
+    JSON,
+    Boolean,
+    Column,
+    DateTime,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+)
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/base.py

@@ -1,17 +1,15 @@
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 from sqlalchemy import Column, DateTime
 
-from app.core.database import Base
-
 
 class TimestampMixin:
     """Mixin to add created_at and updated_at timestamps to models"""
 
-    created_at = Column(DateTime, default=datetime.now(timezone.utc), nullable=False)
+    created_at = Column(DateTime, default=datetime.now(UTC), nullable=False)
     updated_at = Column(
         DateTime,
-        default=datetime.now(timezone.utc),
-        onupdate=datetime.now(timezone.utc),
+        default=datetime.now(UTC),
+        onupdate=datetime.now(UTC),
         nullable=False,
     )

models/database/cart.py

@@ -1,9 +1,16 @@
 # models/database/cart.py
 """Cart item database model."""
-from datetime import datetime
 
-from sqlalchemy import (Column, Float, ForeignKey, Index, Integer, String,
-                        UniqueConstraint)
+
+from sqlalchemy import (
+    Column,
+    Float,
+    ForeignKey,
+    Index,
+    Integer,
+    String,
+    UniqueConstraint,
+)
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/content_page.py

@@ -14,10 +14,19 @@ Features:
 - Version history support
 """
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
-from sqlalchemy import (Boolean, Column, DateTime, ForeignKey, Index, Integer,
-                        String, Text, UniqueConstraint)
+from sqlalchemy import (
+    Boolean,
+    Column,
+    DateTime,
+    ForeignKey,
+    Index,
+    Integer,
+    String,
+    Text,
+    UniqueConstraint,
+)
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base
@@ -77,13 +86,13 @@ class ContentPage(Base):
     # Timestamps
     created_at = Column(
         DateTime(timezone=True),
-        default=lambda: datetime.now(timezone.utc),
+        default=lambda: datetime.now(UTC),
         nullable=False,
     )
     updated_at = Column(
         DateTime(timezone=True),
-        default=lambda: datetime.now(timezone.utc),
-        onupdate=lambda: datetime.now(timezone.utc),
+        default=lambda: datetime.now(UTC),
+        onupdate=lambda: datetime.now(UTC),
         nullable=False,
     )
 

models/database/customer.py

@@ -1,8 +1,14 @@
-from datetime import datetime
-from decimal import Decimal
 
-from sqlalchemy import (JSON, Boolean, Column, DateTime, ForeignKey, Integer,
-                        Numeric, String, Text)
+from sqlalchemy import (
+    JSON,
+    Boolean,
+    Column,
+    DateTime,
+    ForeignKey,
+    Integer,
+    Numeric,
+    String,
+)
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/inventory.py

@@ -1,8 +1,6 @@
 # models/database/inventory.py
-from datetime import datetime
 
-from sqlalchemy import (Column, ForeignKey, Index, Integer, String,
-                        UniqueConstraint)
+from sqlalchemy import Column, ForeignKey, Index, Integer, String, UniqueConstraint
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/marketplace_import_job.py

@@ -1,7 +1,5 @@
-from datetime import datetime, timezone
 
-from sqlalchemy import (Column, DateTime, ForeignKey, Index, Integer, String,
-                        Text)
+from sqlalchemy import Column, DateTime, ForeignKey, Index, Integer, String, Text
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/marketplace_product.py

@@ -1,7 +1,10 @@
-from datetime import datetime, timezone
 
-from sqlalchemy import (Boolean, Column, DateTime, Float, ForeignKey, Index,
-                        Integer, String, Text, UniqueConstraint)
+from sqlalchemy import (
+    Column,
+    Index,
+    Integer,
+    String,
+)
 from sqlalchemy.orm import relationship
 
 # Import Base from the central database module instead of creating a new one

models/database/order.py

@@ -1,8 +1,15 @@
 # models/database/order.py
-from datetime import datetime
 
-from sqlalchemy import (Boolean, Column, DateTime, Float, ForeignKey, Integer,
-                        String, Text)
+from sqlalchemy import (
+    Boolean,
+    Column,
+    DateTime,
+    Float,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+)
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/product.py

@@ -1,8 +1,15 @@
 # models/database/product.py
-from datetime import datetime
 
-from sqlalchemy import (Boolean, Column, Float, ForeignKey, Index, Integer,
-                        String, UniqueConstraint)
+from sqlalchemy import (
+    Boolean,
+    Column,
+    Float,
+    ForeignKey,
+    Index,
+    Integer,
+    String,
+    UniqueConstraint,
+)
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/user.py

@@ -10,9 +10,10 @@ ROLE CLARIFICATION:
 - Vendor-specific roles (manager, staff, etc.) are stored in VendorUser.role
 - Customers are NOT in the User table - they use the Customer model
 """
+
 import enum
 
-from sqlalchemy import Boolean, Column, DateTime, Enum, Integer, String
+from sqlalchemy import Boolean, Column, DateTime, Integer, String
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/vendor.py

@@ -5,13 +5,23 @@ Vendor model representing entities that sell products or services.
 This module defines the Vendor model along with its relationships to
 other models such as User (owner), Product, Customer, Order, and MarketplaceImportJob.
 """
+
 import enum
 
-from sqlalchemy import (JSON, Boolean, Column, DateTime, ForeignKey, Integer,
-                        String, Text)
+from sqlalchemy import (
+    JSON,
+    Boolean,
+    Column,
+    DateTime,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+)
 from sqlalchemy.orm import relationship
 
 from app.core.config import settings
+
 # Import Base from the central database module instead of creating a new one
 from app.core.database import Base
 from models.database.base import TimestampMixin

models/database/vendor_domain.py

@@ -2,10 +2,18 @@
 """
 Vendor Domain Model - Maps custom domains to vendors
 """
-from datetime import datetime, timezone
 
-from sqlalchemy import (Boolean, Column, DateTime, ForeignKey, Index, Integer,
-                        String, UniqueConstraint)
+
+from sqlalchemy import (
+    Boolean,
+    Column,
+    DateTime,
+    ForeignKey,
+    Index,
+    Integer,
+    String,
+    UniqueConstraint,
+)
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base

models/database/vendor_theme.py

@@ -3,6 +3,7 @@
 Vendor Theme Configuration Model
 Allows each vendor to customize their shop's appearance
 """
+
 from sqlalchemy import JSON, Boolean, Column, ForeignKey, Integer, String, Text
 from sqlalchemy.orm import relationship