feat: add administration page and account role management

- Implemented `AdministrationContent` component for managing account roles.
- Created `AdministrationPage` to serve as the main entry point for administration tasks.
- Added PDF preview functionality with `PdfPreviewFrame` component for invoice generation.
- Introduced `InputColor` component for advanced color selection with various formats.
- Established color conversion utilities in `color-converter.ts` for handling color formats.
- Defined appearance-related schemas and types in `appearance.ts` for consistent theme management.

src/components/navigation/breadcrumbs.tsx

@@ -14,12 +14,15 @@ export function Breadcrumbs() {
     })),
   ];
   return (
-    <nav className="flex items-center text-sm text-muted-foreground" aria-label="Breadcrumb">
+    <nav
+      className="text-muted-foreground flex items-center text-sm"
+      aria-label="Breadcrumb"
+    >
       {crumbs.map((crumb, i) => (
         <span key={crumb.href} className="flex items-center">
           {i > 0 && <ChevronRight className="mx-2 h-4 w-4 text-gray-300" />}
           {i < crumbs.length - 1 ? (
-            <Link href={crumb.href} className="hover:underline text-gray-500">
+            <Link href={crumb.href} className="text-gray-500 hover:underline">
               {crumb.name}
             </Link>
           ) : (
@@ -29,4 +32,4 @@ export function Breadcrumbs() {
       ))}
     </nav>
   );
-} 
+}