🚸(frontend) add permissions dialog to guide users through setup

Introduce guided permissions dialog to help users understand and
resolve camera/microphone access issues step-by-step.

Addresses common user support requests where users cannot enable their
hardware and don't understand the permission requirements. Provides
clear instructions to reduce confusion and support burden.

Image was quickly prototyped. It will be updated later on.

src/frontend/src/locales/nl/rooms.json

@@ -77,6 +77,23 @@
     },
     "close": "OK"
   },
+  "permissionErrorDialog": {
+    "heading": {
+      "camera": "{{appTitle}} mag uw camera niet gebruiken",
+      "microphone": "{{appTitle}} mag uw microfoon niet gebruiken",
+      "cameraAndMicrophone": "{{appTitle}} mag uw microfoon en camera niet gebruiken",
+      "default": "{{appTitle}} heeft geen toestemming voor bepaalde rechten"
+    },
+    "body": {
+      "openMenu": "Klik op het instellingenpictogram ICON_PLACEHOLDER in de adresbalk van uw browser",
+      "details": {
+        "camera": "Toegang tot de camera toestaan",
+        "microphone": "Toegang tot de microfoon toestaan",
+        "cameraAndMicrophone": "Toegang tot camera en microfoon toestaan",
+        "default": "Schakel de vereiste machtigingen in."
+      }
+    }
+  },
   "error": {
     "createRoom": {
       "heading": "Verificatie vereist",