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/data/stats-card.tsx

@@ -80,7 +80,7 @@ export function StatsCard({
             )}
           </div>
           {Icon && (
-            <div className={cn(" p-3", styles.background)}>
+            <div className={cn("p-3", styles.background)}>
               <Icon className={cn("h-6 w-6", styles.icon)} />
             </div>
           )}