feat: add admin/profile UI, i18n (fr/de/pt), fix CI pipelines

- Add admin panel link and profile modal in user menu dropdown
- Add French, German and Portuguese locale support (full translations)
- Register new locales across JS frontend and Rust backend
- Create CI pipeline (fmt, clippy, test, audit, build)
- Fix docker-build.yml (cache, real tests, reduced timeout)
- Fix docker-publish.yml (multi-arch via QEMU, latest tag, pre-publish tests)
- Add dependabot.yml for automated dependency updates

static/locales/es.json

@@ -160,7 +160,10 @@
   "user_menu": {
     "appearance": "Apariencia",
     "about": "Acerca de OxiCloud",
-    "about_description": "Plataforma de almacenamiento en la nube creada con Rust y Arquitectura Limpia. Rápida, segura y privada."
+    "about_description": "Plataforma de almacenamiento en la nube creada con Rust y Arquitectura Limpia. Rápida, segura y privada.",
+    "admin_panel": "Panel de administración",
+    "profile": "Mi perfil",
+    "role_user": "Usuario"
   },
   "files": {
     "name": "Nombre",
@@ -302,7 +305,10 @@
       "en": "English",
       "es": "Español",
       "zh": "中文",
-      "fa": "فارسی"
+      "fa": "فارسی",
+      "fr": "Français",
+      "de": "Deutsch",
+      "pt": "Português"
     }
   },
   "favorites": {