feat: add image rendering logs and refactor Icon component

- Add detailed tracing logs for image processing (CBZ, CBR, PDF)
- Add cache hit/miss logging with timing info
- Centralize all SVG icons into reusable Icon component
- Add Settings icon to header navigation
- Add icons for Image Processing, Cache, and Performance Limits sections

apps/backoffice/app/components/ui/index.ts

@@ -17,5 +17,5 @@ export {
   FormField, FormLabel, FormInput, FormSelect, FormRow, 
   FormSection, FormError, FormDescription 
 } from "./Form";
-export { PageIcon, NavIcon } from "./Icon";
+export { PageIcon, NavIcon, Icon } from "./Icon";
 export { CursorPagination, OffsetPagination } from "./Pagination";