v0.25.0 — Debug page: operator testing & diagnostics dashboard

Debug-mode-only dashboard (/debug) with 8 collapsible sections:
system diagnostics, notification testing, backup triggers, storage
simulation, hub & connectivity, self-update dry-run, DR/setup wizard,
and in-memory log viewer. Migrates debug dump from API router to web
server. Adds ring buffer log capture, storage disconnect simulation,
event history tracking, and cross-drive/self-update test methods.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/web/templates/layout.html

@@ -20,6 +20,7 @@
             <li><a href="/stacks" class="{{if eq .Page "stacks"}}active{{end}}">Alkalmazások</a></li>
             <li><a href="/backups" class="{{if eq .Page "backups"}}active{{end}}">Biztonsági mentés</a></li>
             <li><a href="/monitoring" class="{{if eq .Page "monitoring"}}active{{end}}">Rendszermonitor</a></li>
+            {{if .DebugMode}}<li><a href="/debug" class="{{if eq .Page "debug"}}active{{end}}">🔧 Debug</a></li>{{end}}
         </ul>
         <div class="sidebar-bottom">
             <a href="/settings" class="sidebar-settings-link {{if eq .Page "settings"}}active{{end}}">⚙ Beállítások</a>