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/schema/vendor.py

@@ -15,7 +15,7 @@ Schemas include:
 
 import re
 from datetime import datetime
-from typing import Any, Dict, List, Optional
+from typing import Any
 
 from pydantic import BaseModel, ConfigDict, Field, field_validator
 
@@ -36,7 +36,7 @@ class VendorCreate(BaseModel):
     name: str = Field(
         ..., description="Display name of the vendor", min_length=2, max_length=255
     )
-    description: Optional[str] = Field(None, description="Vendor description")
+    description: str | None = Field(None, description="Vendor description")
 
     # Owner Information (Creates User Account)
     owner_email: str = Field(
@@ -45,21 +45,21 @@ class VendorCreate(BaseModel):
     )
 
     # Business Contact Information (Vendor Fields)
-    contact_email: Optional[str] = Field(
+    contact_email: str | None = Field(
         None,
         description="Public business contact email (defaults to owner_email if not provided)",
     )
-    contact_phone: Optional[str] = Field(None, description="Contact phone number")
-    website: Optional[str] = Field(None, description="Website URL")
+    contact_phone: str | None = Field(None, description="Contact phone number")
+    website: str | None = Field(None, description="Website URL")
 
     # Business Details
-    business_address: Optional[str] = Field(None, description="Business address")
-    tax_number: Optional[str] = Field(None, description="Tax/VAT number")
+    business_address: str | None = Field(None, description="Business address")
+    tax_number: str | None = Field(None, description="Tax/VAT number")
 
     # Marketplace URLs (multi-language support)
-    letzshop_csv_url_fr: Optional[str] = Field(None, description="French CSV URL")
-    letzshop_csv_url_en: Optional[str] = Field(None, description="English CSV URL")
-    letzshop_csv_url_de: Optional[str] = Field(None, description="German CSV URL")
+    letzshop_csv_url_fr: str | None = Field(None, description="French CSV URL")
+    letzshop_csv_url_en: str | None = Field(None, description="English CSV URL")
+    letzshop_csv_url_de: str | None = Field(None, description="German CSV URL")
 
     @field_validator("owner_email", "contact_email")
     @classmethod
@@ -95,29 +95,29 @@ class VendorUpdate(BaseModel):
     """
 
     # Basic Information
-    name: Optional[str] = Field(None, min_length=2, max_length=255)
-    description: Optional[str] = None
-    subdomain: Optional[str] = Field(None, min_length=2, max_length=100)
+    name: str | None = Field(None, min_length=2, max_length=255)
+    description: str | None = None
+    subdomain: str | None = Field(None, min_length=2, max_length=100)
 
     # Business Contact Information (Vendor Fields)
-    contact_email: Optional[str] = Field(
+    contact_email: str | None = Field(
         None, description="Public business contact email"
     )
-    contact_phone: Optional[str] = None
-    website: Optional[str] = None
+    contact_phone: str | None = None
+    website: str | None = None
 
     # Business Details
-    business_address: Optional[str] = None
-    tax_number: Optional[str] = None
+    business_address: str | None = None
+    tax_number: str | None = None
 
     # Marketplace URLs
-    letzshop_csv_url_fr: Optional[str] = None
-    letzshop_csv_url_en: Optional[str] = None
-    letzshop_csv_url_de: Optional[str] = None
+    letzshop_csv_url_fr: str | None = None
+    letzshop_csv_url_en: str | None = None
+    letzshop_csv_url_de: str | None = None
 
     # Status (Admin only)
-    is_active: Optional[bool] = None
-    is_verified: Optional[bool] = None
+    is_active: bool | None = None
+    is_verified: bool | None = None
 
     @field_validator("subdomain")
     @classmethod
@@ -145,22 +145,22 @@ class VendorResponse(BaseModel):
     vendor_code: str
     subdomain: str
     name: str
-    description: Optional[str]
+    description: str | None
     owner_user_id: int
 
     # Contact Information (Business)
-    contact_email: Optional[str]
-    contact_phone: Optional[str]
-    website: Optional[str]
+    contact_email: str | None
+    contact_phone: str | None
+    website: str | None
 
     # Business Information
-    business_address: Optional[str]
-    tax_number: Optional[str]
+    business_address: str | None
+    tax_number: str | None
 
     # Marketplace URLs
-    letzshop_csv_url_fr: Optional[str]
-    letzshop_csv_url_en: Optional[str]
-    letzshop_csv_url_de: Optional[str]
+    letzshop_csv_url_fr: str | None
+    letzshop_csv_url_en: str | None
+    letzshop_csv_url_de: str | None
 
     # Status Flags
     is_active: bool
@@ -196,13 +196,13 @@ class VendorCreateResponse(VendorDetailResponse):
     temporary_password: str = Field(
         ..., description="Temporary password for owner (SHOWN ONLY ONCE)"
     )
-    login_url: Optional[str] = Field(None, description="URL for vendor owner to login")
+    login_url: str | None = Field(None, description="URL for vendor owner to login")
 
 
 class VendorListResponse(BaseModel):
     """Schema for paginated vendor list."""
 
-    vendors: List[VendorResponse]
+    vendors: list[VendorResponse]
     total: int
     skip: int
     limit: int
@@ -237,7 +237,7 @@ class VendorTransferOwnership(BaseModel):
         ..., description="Must be true to confirm ownership transfer"
     )
 
-    transfer_reason: Optional[str] = Field(
+    transfer_reason: str | None = Field(
         None,
         max_length=500,
         description="Reason for ownership transfer (for audit logs)",
@@ -260,12 +260,12 @@ class VendorTransferOwnershipResponse(BaseModel):
     vendor_code: str
     vendor_name: str
 
-    old_owner: Dict[str, Any] = Field(
+    old_owner: dict[str, Any] = Field(
         ..., description="Information about the previous owner"
     )
-    new_owner: Dict[str, Any] = Field(
+    new_owner: dict[str, Any] = Field(
         ..., description="Information about the new owner"
     )
 
     transferred_at: datetime
-    transfer_reason: Optional[str]
+    transfer_reason: str | None