fix: protect critical re-export imports from linter removal

Problem:
- Ruff removed 'from app.core.database import Base' from models/database/base.py
- Import appeared "unused" (F401) but was actually a critical re-export
- Caused ImportError: cannot import name 'Base' at runtime
- Re-export pattern: import in one file to export from package

Solution:
1. Added F401 ignore for models/database/base.py in pyproject.toml
2. Created scripts/verify_critical_imports.py verification script
3. Integrated verification into make check and CI pipeline
4. Updated documentation with explanation

New Verification Script:
- Checks all critical re-export imports exist
- Detects import variations (parentheses, 'as' clauses)
- Handles SQLAlchemy declarative_base alternatives
- Runs as part of make check automatically

Protected Files:
- models/database/base.py - Re-exports Base for all models
- models/__init__.py - Exports Base for Alembic
- models/database/__init__.py - Exports Base from package
- All __init__.py files (already protected)

Makefile Changes:
- make verify-imports - Run import verification
- make check - Now includes verify-imports
- make ci - Includes verify-imports in pipeline

Documentation Updated:
- Code quality guide explains re-export protection
- Pre-commit workflow includes verification
- Examples of why re-exports matter

This prevents future issues where linters remove seemingly
"unused" imports that are actually critical for application structure.

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

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

models/schema/cart.py

@@ -3,7 +3,6 @@
 Pydantic schemas for shopping cart operations.
 """
 
-
 from pydantic import BaseModel, ConfigDict, Field
 
 # ============================================================================

models/schema/product.py

@@ -11,9 +11,7 @@ class ProductCreate(BaseModel):
     marketplace_product_id: int = Field(
         ..., description="MarketplaceProduct ID to add to vendor catalog"
     )
-    product_id: str | None = Field(
-        None, description="Vendor's internal SKU/product ID"
-    )
+    product_id: str | None = Field(None, description="Vendor's internal SKU/product ID")
     price: float | None = Field(None, ge=0)
     sale_price: float | None = Field(None, ge=0)
     currency: str | None = None

models/schema/team.py

@@ -31,7 +31,6 @@ class RoleCreate(RoleBase):
     """Schema for creating a role."""
 
 
-
 class RoleUpdate(BaseModel):
     """Schema for updating a role."""
 

models/schema/vendor.py

@@ -100,9 +100,7 @@ class VendorUpdate(BaseModel):
     subdomain: str | None = Field(None, min_length=2, max_length=100)
 
     # Business Contact Information (Vendor Fields)
-    contact_email: str | None = Field(
-        None, description="Public business contact email"
-    )
+    contact_email: str | None = Field(None, description="Public business contact email")
     contact_phone: str | None = None
     website: str | None = None
 

models/schema/vendor_theme.py

@@ -3,7 +3,6 @@
 Pydantic schemas for vendor theme operations.
 """
 
-
 from pydantic import BaseModel, Field
 
 
@@ -54,14 +53,10 @@ class VendorThemeUpdate(BaseModel):
     theme_name: str | None = Field(None, description="Theme preset name")
     colors: dict[str, str] | None = Field(None, description="Color scheme")
     fonts: dict[str, str] | None = Field(None, description="Font settings")
-    branding: dict[str, str | None] | None = Field(
-        None, description="Branding assets"
-    )
+    branding: dict[str, str | None] | None = Field(None, description="Branding assets")
     layout: dict[str, str] | None = Field(None, description="Layout settings")
     custom_css: str | None = Field(None, description="Custom CSS rules")
-    social_links: dict[str, str] | None = Field(
-        None, description="Social media links"
-    )
+    social_links: dict[str, str] | None = Field(None, description="Social media links")
 
 
 class VendorThemeResponse(BaseModel):