Add Quiz feature: 10-question quizzes with progressive scoring (max 40 pts)

- Quizzes table with questions, answer options, attempts, answers
- Question types: multiple_choice, exclusion, true_false, free_text
- Progressive scoring: [1,1,2,2,3,3,4,6,8,10] = max 40 per quiz
- Alpine.js countdown timer per question with auto-submit on timeout
- Admin: CRUD for quizzes + per-question editor, JSON export/import
- Child: quiz overview with best scores, question view, result breakdown
- Nav: Quiz link in child header and admin sidebar

resources/views/child/quiz/index.blade.php

@@ -0,0 +1,46 @@
+@extends('layouts.child')
+@section('content')
+<h1 class="text-2xl font-bold text-indigo-700 mb-2">🧠 Quiz</h1>
+<p class="text-slate-500 mb-6">Beantworte 10 Fragen – max. 40 Münzen zu gewinnen!</p>
+
+@foreach($subjects as $subjectId => $subject)
+@php $group = $quizzes->get($subjectId, collect()) @endphp
+@if($group->isNotEmpty())
+<div class="mb-6">
+  <h2 class="font-bold text-slate-600 text-sm uppercase tracking-wide mb-3">{{ $subject->icon }} {{ $subject->name }}</h2>
+  <div class="grid gap-3">
+    @foreach($group as $quiz)
+    <div class="bg-white rounded-2xl border border-slate-200 shadow-sm px-5 py-4">
+      <div class="flex items-start justify-between gap-4">
+        <div class="flex-1 min-w-0">
+          <h3 class="font-bold text-slate-800 text-base">{{ $quiz->title }}</h3>
+          @if($quiz->description)<p class="text-sm text-slate-500 mt-0.5">{{ $quiz->description }}</p>@endif
+          <div class="flex items-center gap-3 mt-2 text-xs text-slate-400">
+            <span>📝 {{ $quiz->questions_count }} Fragen</span>
+            <span>🏆 max. 40 Münzen</span>
+            @if(isset($bestScores[$quiz->id]))
+            <span class="text-amber-600 font-medium">Bisher: {{ $bestScores[$quiz->id] }}/40 🪙</span>
+            @endif
+          </div>
+        </div>
+        <form method="POST" action="{{ route('quiz.start',$quiz) }}">
+          @csrf
+          <button class="bg-indigo-600 hover:bg-indigo-700 text-white px-5 py-2.5 rounded-xl text-sm font-bold whitespace-nowrap">
+            {{ isset($bestScores[$quiz->id]) ? 'Nochmal' : 'Starten' }} →
+          </button>
+        </form>
+      </div>
+    </div>
+    @endforeach
+  </div>
+</div>
+@endif
+@endforeach
+
+@if($quizzes->isEmpty())
+<div class="text-center py-16 text-slate-400">
+  <p class="text-4xl mb-3">🧩</p>
+  <p>Noch keine Quizzes verfügbar. Schau später nochmal vorbei!</p>
+</div>
+@endif
+@endsection