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>

app/api/v1/admin/content_pages.py

@@ -9,7 +9,6 @@ Platform administrators can:
 """
 
 import logging
-from typing import List, Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Query
 from pydantic import BaseModel, Field
@@ -46,17 +45,17 @@ class ContentPageCreate(BaseModel):
         max_length=50,
         description="Template name (default, minimal, modern)",
     )
-    meta_description: Optional[str] = Field(
+    meta_description: str | None = Field(
         None, max_length=300, description="SEO meta description"
     )
-    meta_keywords: Optional[str] = Field(
+    meta_keywords: str | None = Field(
         None, max_length=300, description="SEO keywords"
     )
     is_published: bool = Field(default=False, description="Publish immediately")
     show_in_footer: bool = Field(default=True, description="Show in footer navigation")
     show_in_header: bool = Field(default=False, description="Show in header navigation")
     display_order: int = Field(default=0, description="Display order (lower = first)")
-    vendor_id: Optional[int] = Field(
+    vendor_id: int | None = Field(
         None, description="Vendor ID (None for platform default)"
     )
 
@@ -64,32 +63,32 @@ class ContentPageCreate(BaseModel):
 class ContentPageUpdate(BaseModel):
     """Schema for updating a content page."""
 
-    title: Optional[str] = Field(None, max_length=200)
-    content: Optional[str] = None
-    content_format: Optional[str] = None
-    template: Optional[str] = Field(None, max_length=50)
-    meta_description: Optional[str] = Field(None, max_length=300)
-    meta_keywords: Optional[str] = Field(None, max_length=300)
-    is_published: Optional[bool] = None
-    show_in_footer: Optional[bool] = None
-    show_in_header: Optional[bool] = None
-    display_order: Optional[int] = None
+    title: str | None = Field(None, max_length=200)
+    content: str | None = None
+    content_format: str | None = None
+    template: str | None = Field(None, max_length=50)
+    meta_description: str | None = Field(None, max_length=300)
+    meta_keywords: str | None = Field(None, max_length=300)
+    is_published: bool | None = None
+    show_in_footer: bool | None = None
+    show_in_header: bool | None = None
+    display_order: int | None = None
 
 
 class ContentPageResponse(BaseModel):
     """Schema for content page response."""
 
     id: int
-    vendor_id: Optional[int]
-    vendor_name: Optional[str]
+    vendor_id: int | None
+    vendor_name: str | None
     slug: str
     title: str
     content: str
     content_format: str
-    meta_description: Optional[str]
-    meta_keywords: Optional[str]
+    meta_description: str | None
+    meta_keywords: str | None
     is_published: bool
-    published_at: Optional[str]
+    published_at: str | None
     display_order: int
     show_in_footer: bool
     show_in_header: bool
@@ -97,8 +96,8 @@ class ContentPageResponse(BaseModel):
     is_vendor_override: bool
     created_at: str
     updated_at: str
-    created_by: Optional[int]
-    updated_by: Optional[int]
+    created_by: int | None
+    updated_by: int | None
 
 
 # ============================================================================
@@ -106,7 +105,7 @@ class ContentPageResponse(BaseModel):
 # ============================================================================
 
 
-@router.get("/platform", response_model=List[ContentPageResponse])
+@router.get("/platform", response_model=list[ContentPageResponse])
 def list_platform_pages(
     include_unpublished: bool = Query(False, description="Include draft pages"),
     current_user: User = Depends(get_current_admin_api),
@@ -161,9 +160,9 @@ def create_platform_page(
 # ============================================================================
 
 
-@router.get("/", response_model=List[ContentPageResponse])
+@router.get("/", response_model=list[ContentPageResponse])
 def list_all_pages(
-    vendor_id: Optional[int] = Query(None, description="Filter by vendor ID"),
+    vendor_id: int | None = Query(None, description="Filter by vendor ID"),
     include_unpublished: bool = Query(False, description="Include draft pages"),
     current_user: User = Depends(get_current_admin_api),
     db: Session = Depends(get_db),
@@ -256,4 +255,4 @@ def delete_page(
     if not success:
         raise HTTPException(status_code=404, detail="Content page not found")
 
-    return None
+    return