style: apply black and isort formatting across entire codebase

- Standardize quote style (single to double quotes)
- Reorder and group imports alphabetically
- Fix line breaks and indentation for consistency
- Apply PEP 8 formatting standards

Also updated Makefile to exclude both venv and .venv from code quality checks.

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

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

models/database/vendor_domain.py

@@ -3,11 +3,11 @@
 Vendor Domain Model - Maps custom domains to vendors
 """
 from datetime import datetime, timezone
-from sqlalchemy import (
-    Column, Integer, String, Boolean, DateTime,
-    ForeignKey, UniqueConstraint, Index
-)
+
+from sqlalchemy import (Boolean, Column, DateTime, ForeignKey, Index, Integer,
+                        String, UniqueConstraint)
 from sqlalchemy.orm import relationship
+
 from app.core.database import Base
 from models.database.base import TimestampMixin
 
@@ -21,10 +21,13 @@ class VendorDomain(Base, TimestampMixin):
     - shop.mybusiness.com → Vendor 2
     - www.customdomain1.com → Vendor 1 (www is stripped)
     """
+
     __tablename__ = "vendor_domains"
 
     id = Column(Integer, primary_key=True, index=True)
-    vendor_id = Column(Integer, ForeignKey("vendors.id", ondelete="CASCADE"), nullable=False)
+    vendor_id = Column(
+        Integer, ForeignKey("vendors.id", ondelete="CASCADE"), nullable=False
+    )
 
     # Domain configuration
     domain = Column(String(255), nullable=False, unique=True, index=True)
@@ -32,7 +35,9 @@ class VendorDomain(Base, TimestampMixin):
     is_active = Column(Boolean, default=True, nullable=False)
 
     # SSL/TLS status (for monitoring)
-    ssl_status = Column(String(50), default="pending")  # pending, active, expired, error
+    ssl_status = Column(
+        String(50), default="pending"
+    )  # pending, active, expired, error
     ssl_verified_at = Column(DateTime(timezone=True), nullable=True)
 
     # DNS verification (to confirm domain ownership)
@@ -45,9 +50,9 @@ class VendorDomain(Base, TimestampMixin):
 
     # Constraints
     __table_args__ = (
-        UniqueConstraint('vendor_id', 'domain', name='uq_vendor_domain'),
-        Index('idx_domain_active', 'domain', 'is_active'),
-        Index('idx_vendor_primary', 'vendor_id', 'is_primary'),
+        UniqueConstraint("vendor_id", "domain", name="uq_vendor_domain"),
+        Index("idx_domain_active", "domain", "is_active"),
+        Index("idx_vendor_primary", "vendor_id", "is_primary"),
     )
 
     def __repr__(self):