fix: rename application from Keep to Mento in UI and docs

- Update sidebar.tsx to display "Mento" instead of "Keep"
- Update README.md title from "Keep Notes" to "Mento"
- Update DOCKER_DEPLOYMENT.md references to "Mento"
- Update deploy.sh script comments to use "Mento"
- Add DOCKER-SETUP.md with Docker configuration guide

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

keep-notes/components/sidebar.tsx

@@ -79,7 +79,7 @@ export function Sidebar({ className, user }: { className?: string, user?: any })
             <StickyNote className="h-5 w-5" />
           </div>
           <div className="flex flex-col">
-            <span className="text-lg font-bold tracking-tight text-slate-900 dark:text-white leading-none">Keep</span>
+            <span className="text-lg font-bold tracking-tight text-slate-900 dark:text-white leading-none">Mento</span>
             <span className="text-[10px] font-medium text-slate-400 dark:text-slate-500 uppercase tracking-widest mt-1">{t('nav.workspace')}</span>
           </div>
         </div>