refactor: extract Installation Guides into block renderer components

Replace monolithic Connection.tsx (1076 lines) with modular architecture:
- 4 block renderers (cards, timeline, accordion, minimal) selectable
  via uiConfig.installationGuidesBlockType from RemnaWave config
- Color parser utility with 14 named colors + hex support
- InstallationGuide component handles platform/app selection and
  button rendering (subscriptionLink, copyButton, external)
- Remove classic step-based format (AppButton, AppStep, AppInfo)
- Add appConfig query invalidation on admin UUID change

src/pages/AdminApps.tsx

@@ -36,6 +36,7 @@ export default function AdminApps() {
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ['remnawave-status'] });
       queryClient.invalidateQueries({ queryKey: ['remnawave-config'] });
+      queryClient.invalidateQueries({ queryKey: ['appConfig'] });
     },
   });