refactor: move vendor product schemas to models/schema and add API-002 rule

- Add API-002 architecture rule preventing Pydantic imports in API endpoints
- Move inline Pydantic models from vendor_products.py to models/schema/vendor_product.py
- Update vendor_products.py to import schemas from proper location

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

models/schema/vendor_product.py

@@ -0,0 +1,145 @@
+# models/schema/vendor_product.py
+"""
+Pydantic schemas for vendor product catalog operations.
+
+Used by admin vendor product endpoints for:
+- Product listing and filtering
+- Product statistics
+- Product detail views
+- Catalog vendor listings
+"""
+
+from pydantic import BaseModel, ConfigDict
+
+
+class VendorProductListItem(BaseModel):
+    """Product item for vendor catalog list view."""
+
+    model_config = ConfigDict(from_attributes=True)
+
+    id: int
+    vendor_id: int
+    vendor_name: str | None = None
+    vendor_code: str | None = None
+    marketplace_product_id: int
+    vendor_sku: str | None = None
+    title: str | None = None
+    brand: str | None = None
+    effective_price: float | None = None
+    effective_currency: str | None = None
+    is_active: bool | None = None
+    is_featured: bool | None = None
+    is_digital: bool | None = None
+    image_url: str | None = None
+    source_marketplace: str | None = None
+    source_vendor: str | None = None
+    created_at: str | None = None
+    updated_at: str | None = None
+
+
+class VendorProductListResponse(BaseModel):
+    """Paginated vendor product list response."""
+
+    products: list[VendorProductListItem]
+    total: int
+    skip: int
+    limit: int
+
+
+class VendorProductStats(BaseModel):
+    """Vendor product statistics."""
+
+    total: int
+    active: int
+    inactive: int
+    featured: int
+    digital: int
+    physical: int
+    by_vendor: dict[str, int]
+
+
+class CatalogVendor(BaseModel):
+    """Vendor with products in catalog."""
+
+    id: int
+    name: str
+    vendor_code: str
+
+
+class CatalogVendorsResponse(BaseModel):
+    """Response for catalog vendors list."""
+
+    vendors: list[CatalogVendor]
+
+
+class VendorProductDetail(BaseModel):
+    """Detailed vendor product information."""
+
+    id: int
+    vendor_id: int
+    vendor_name: str | None = None
+    vendor_code: str | None = None
+    marketplace_product_id: int
+    vendor_sku: str | None = None
+    # Override info from get_override_info()
+    price: float | None = None
+    price_overridden: bool | None = None
+    price_source: float | None = None
+    sale_price: float | None = None
+    sale_price_overridden: bool | None = None
+    sale_price_source: float | None = None
+    currency: str | None = None
+    currency_overridden: bool | None = None
+    currency_source: str | None = None
+    brand: str | None = None
+    brand_overridden: bool | None = None
+    brand_source: str | None = None
+    condition: str | None = None
+    condition_overridden: bool | None = None
+    condition_source: str | None = None
+    availability: str | None = None
+    availability_overridden: bool | None = None
+    availability_source: str | None = None
+    primary_image_url: str | None = None
+    primary_image_url_overridden: bool | None = None
+    primary_image_url_source: str | None = None
+    is_digital: bool | None = None
+    product_type: str | None = None
+    # Vendor-specific fields
+    is_featured: bool | None = None
+    is_active: bool | None = None
+    display_order: int | None = None
+    min_quantity: int | None = None
+    max_quantity: int | None = None
+    # Supplier tracking
+    supplier: str | None = None
+    supplier_product_id: str | None = None
+    cost: float | None = None  # What vendor pays to acquire product
+    margin_percent: float | None = None
+    # Tax/profit info
+    tax_rate_percent: int | None = None
+    net_price: float | None = None
+    vat_amount: float | None = None
+    profit: float | None = None
+    profit_margin_percent: float | None = None
+    # Digital fulfillment
+    download_url: str | None = None
+    license_type: str | None = None
+    fulfillment_email_template: str | None = None
+    # Source info
+    source_marketplace: str | None = None
+    source_vendor: str | None = None
+    source_gtin: str | None = None
+    source_sku: str | None = None
+    # Translations
+    marketplace_translations: dict | None = None
+    vendor_translations: dict | None = None
+    # Timestamps
+    created_at: str | None = None
+    updated_at: str | None = None
+
+
+class RemoveProductResponse(BaseModel):
+    """Response from product removal."""
+
+    message: str