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/content_page.py

@@ -15,7 +15,9 @@ Features:
 """
 
 from datetime import datetime, timezone
-from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Integer, String, Text, UniqueConstraint, Index
+
+from sqlalchemy import (Boolean, Column, DateTime, ForeignKey, Index, Integer,
+                        String, Text, UniqueConstraint)
 from sqlalchemy.orm import relationship
 
 from app.core.database import Base
@@ -34,15 +36,20 @@ class ContentPage(Base):
     2. If not found, use platform default (slug only)
     3. If neither exists, show 404 or default template
     """
+
     __tablename__ = "content_pages"
 
     id = Column(Integer, primary_key=True, index=True)
 
     # Vendor association (NULL = platform default)
-    vendor_id = Column(Integer, ForeignKey("vendors.id", ondelete="CASCADE"), nullable=True, index=True)
+    vendor_id = Column(
+        Integer, ForeignKey("vendors.id", ondelete="CASCADE"), nullable=True, index=True
+    )
 
     # Page identification
-    slug = Column(String(100), nullable=False, index=True)  # about, faq, contact, shipping, returns, etc.
+    slug = Column(
+        String(100), nullable=False, index=True
+    )  # about, faq, contact, shipping, returns, etc.
     title = Column(String(200), nullable=False)
 
     # Content
@@ -68,12 +75,25 @@ class ContentPage(Base):
     show_in_header = Column(Boolean, default=False)
 
     # Timestamps
-    created_at = Column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False)
-    updated_at = Column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc), nullable=False)
+    created_at = Column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        nullable=False,
+    )
+    updated_at = Column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+        nullable=False,
+    )
 
     # Author tracking (admin or vendor user who created/updated)
-    created_by = Column(Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
-    updated_by = Column(Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
+    created_by = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True
+    )
+    updated_by = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True
+    )
 
     # Relationships
     vendor = relationship("Vendor", back_populates="content_pages")
@@ -84,11 +104,10 @@ class ContentPage(Base):
     __table_args__ = (
         # Unique combination: vendor can only have one page per slug
         # Platform defaults (vendor_id=NULL) can only have one page per slug
-        UniqueConstraint('vendor_id', 'slug', name='uq_vendor_slug'),
-
+        UniqueConstraint("vendor_id", "slug", name="uq_vendor_slug"),
         # Indexes for performance
-        Index('idx_vendor_published', 'vendor_id', 'is_published'),
-        Index('idx_slug_published', 'slug', 'is_published'),
+        Index("idx_vendor_published", "vendor_id", "is_published"),
+        Index("idx_slug_published", "slug", "is_published"),
     )
 
     def __repr__(self):
@@ -119,7 +138,9 @@ class ContentPage(Base):
             "meta_description": self.meta_description,
             "meta_keywords": self.meta_keywords,
             "is_published": self.is_published,
-            "published_at": self.published_at.isoformat() if self.published_at else None,
+            "published_at": (
+                self.published_at.isoformat() if self.published_at else None
+            ),
             "display_order": self.display_order,
             "show_in_footer": self.show_in_footer,
             "show_in_header": self.show_in_header,