Improve app navigation and settings by adding new translations

Update i18n files for English and German, and refactor BottomNavigation and Settings components to use translated strings for navigation and settings options.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ceced2fc-aa46-458d-ba87-ddd4b7bb1518
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/659922a9-0087-461c-90dd-6d9a58b81d4d/ceced2fc-aa46-458d-ba87-ddd4b7bb1518/un1X8jl

client/src/pages/settings.tsx

@@ -58,7 +58,7 @@ export default function Settings() {
         </CardHeader>
         <CardContent>
           <p className="text-sm text-muted-foreground">
-            Theme toggle available in the header
+            {t('settings.appearance.themeToggle')}
           </p>
         </CardContent>
       </Card>
@@ -73,7 +73,7 @@ export default function Settings() {
         </CardHeader>
         <CardContent>
           <p className="text-sm text-muted-foreground">
-            Access templates from the navigation menu
+            {t('settings.templates.accessInfo')}
           </p>
         </CardContent>
       </Card>