feat: add platform homepage and content management system with improved UI

Implemented a comprehensive CMS for managing platform homepage and content pages:

- Platform homepage manager with template selection (default, minimal, modern)
- Content pages CRUD with platform defaults and vendor overrides
- Sidebar navigation for Content Management section
- Dedicated API endpoints for creating, updating, deleting pages
- Template support for customizable homepage layouts
- Header/footer navigation integration for content pages
- Comprehensive documentation for platform homepage setup
- Migration script for creating initial platform pages

UI improvements:
- Fixed action buttons styling in content pages table to match design system
- Added proper hover states, rounded corners, and better contrast
- Increased button size and padding for better usability

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

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

main.py

@@ -272,6 +272,138 @@ async def vendor_root_path(vendor_code: str, request: Request, db: Session = Dep
         # No landing page - redirect to shop
         return RedirectResponse(url=f"/vendors/{vendor_code}/shop/", status_code=302)
 
+
+# ============================================================================
+# PLATFORM PUBLIC PAGES (Platform Homepage, About, FAQ, etc.)
+# ============================================================================
+logger.info("Registering platform public page routes:")
+logger.info("  - / (platform homepage)")
+logger.info("  - /{slug} (platform content pages: /about, /faq, /terms, /contact)")
+
+
+@app.get("/", response_class=HTMLResponse, include_in_schema=False)
+async def platform_homepage(request: Request, db: Session = Depends(get_db)):
+    """
+    Platform homepage at localhost:8000 or platform.com
+
+    Looks for CMS page with slug='platform_homepage' (vendor_id=NULL)
+    Falls back to default static template if not found.
+    """
+    from app.services.content_page_service import content_page_service
+
+    logger.debug("[PLATFORM] Homepage requested")
+
+    # Try to load platform homepage from CMS
+    homepage = content_page_service.get_page_for_vendor(
+        db,
+        slug="platform_homepage",
+        vendor_id=None,  # Platform-level page
+        include_unpublished=False
+    )
+
+    # Load header and footer navigation
+    header_pages = content_page_service.list_pages_for_vendor(
+        db,
+        vendor_id=None,
+        header_only=True,
+        include_unpublished=False
+    )
+
+    footer_pages = content_page_service.list_pages_for_vendor(
+        db,
+        vendor_id=None,
+        footer_only=True,
+        include_unpublished=False
+    )
+
+    if homepage:
+        # Use template selection from CMS
+        template_name = homepage.template or "default"
+        template_path = f"platform/homepage-{template_name}.html"
+
+        logger.info(f"[PLATFORM] Rendering CMS homepage with template: {template_path}")
+
+        return templates.TemplateResponse(
+            template_path,
+            {
+                "request": request,
+                "page": homepage,
+                "header_pages": header_pages,
+                "footer_pages": footer_pages,
+            }
+        )
+    else:
+        # Fallback to default static template
+        logger.info("[PLATFORM] No CMS homepage found, using default template")
+
+        return templates.TemplateResponse(
+            "platform/homepage-default.html",
+            {
+                "request": request,
+                "header_pages": header_pages,
+                "footer_pages": footer_pages,
+            }
+        )
+
+
+@app.get("/{slug}", response_class=HTMLResponse, include_in_schema=False)
+async def platform_content_page(
+    request: Request,
+    slug: str,
+    db: Session = Depends(get_db)
+):
+    """
+    Platform content pages: /about, /faq, /terms, /contact, etc.
+
+    Loads content from CMS with slug (vendor_id=NULL for platform pages).
+    Returns 404 if page not found.
+
+    This route MUST be defined LAST to avoid conflicts with other routes.
+    """
+    from app.services.content_page_service import content_page_service
+
+    logger.debug(f"[PLATFORM] Content page requested: /{slug}")
+
+    # Load page from CMS
+    page = content_page_service.get_page_for_vendor(
+        db,
+        slug=slug,
+        vendor_id=None,  # Platform pages only
+        include_unpublished=False
+    )
+
+    if not page:
+        logger.warning(f"[PLATFORM] Content page not found: {slug}")
+        raise HTTPException(status_code=404, detail=f"Page not found: {slug}")
+
+    # Load header and footer navigation
+    header_pages = content_page_service.list_pages_for_vendor(
+        db,
+        vendor_id=None,
+        header_only=True,
+        include_unpublished=False
+    )
+
+    footer_pages = content_page_service.list_pages_for_vendor(
+        db,
+        vendor_id=None,
+        footer_only=True,
+        include_unpublished=False
+    )
+
+    logger.info(f"[PLATFORM] Rendering content page: {page.title} (/{slug})")
+
+    return templates.TemplateResponse(
+        "platform/content-page.html",
+        {
+            "request": request,
+            "page": page,
+            "header_pages": header_pages,
+            "footer_pages": footer_pages,
+        }
+    )
+
+
 logger.info("=" * 80)
 
 # Log all registered routes