Add grade/Klasse system: assign class levels to users, questions, and quizzes

- users.grade: set per child in admin (Klasse 1–10)
- quizzes.grade, questions.grade: optional target class (null = all)
- Children only see content matching their grade or without grade set
- Admin views show grade badge in user list, quiz list, questions list
- Quiz create/edit and user create/edit have Klasse dropdown

app/Http/Controllers/Admin/QuizController.php

@@ -18,8 +18,8 @@ class QuizController extends Controller {
     }
 
     public function store(Request $r) {
-        $r->validate(['title'=>'required|string|max:120','subject_id'=>'required|exists:subjects,id','description'=>'nullable|string|max:500']);
+        $r->validate(['title'=>'required|string|max:120','subject_id'=>'required|exists:subjects,id','description'=>'nullable|string|max:500','grade'=>'nullable|integer|min:1|max:13']);
-        $quiz = Quiz::create($r->only('title','subject_id','description') + ['active'=>true]);
+        $quiz = Quiz::create($r->only('title','subject_id','description') + ['active'=>true,'grade'=>$r->grade ?: null]);
         return redirect()->route('admin.quizzes.edit', $quiz)->with('success','Quiz erstellt – jetzt Fragen hinzufügen.');
     }
 
@@ -30,8 +30,8 @@ class QuizController extends Controller {
     }
 
     public function update(Request $r, Quiz $quiz) {
-        $r->validate(['title'=>'required|string|max:120','subject_id'=>'required|exists:subjects,id','description'=>'nullable|string|max:500']);
+        $r->validate(['title'=>'required|string|max:120','subject_id'=>'required|exists:subjects,id','description'=>'nullable|string|max:500','grade'=>'nullable|integer|min:1|max:13']);
-        $quiz->update($r->only('title','subject_id','description') + ['active'=>$r->boolean('active')]);
+        $quiz->update($r->only('title','subject_id','description') + ['active'=>$r->boolean('active'),'grade'=>$r->grade ?: null]);
         return back()->with('success','Quiz gespeichert.');
     }
 

app/Http/Controllers/Admin/UserController.php

@@ -15,6 +15,7 @@ class UserController extends Controller {
             'name'     => 'required|string|max:60',
             'email'    => 'required|email|unique:users',
             'password' => 'required|min:6',
+            'grade'    => 'nullable|integer|min:1|max:13',
         ]);
         User::create([
             'name'     => $r->name,
@@ -22,6 +23,7 @@ class UserController extends Controller {
             'password' => Hash::make($r->password),
             'role'     => 'child',
             'points'   => 0,
+            'grade'    => $r->grade ?: null,
         ]);
         return redirect()->route('admin.users.index')->with('success','Kind-Konto erstellt.');
     }
@@ -32,8 +34,9 @@ class UserController extends Controller {
             'email'    => 'required|email|unique:users,email,'.$user->id,
             'password' => 'nullable|min:6',
             'points'   => 'required|integer|min:0',
+            'grade'    => 'nullable|integer|min:1|max:13',
         ]);
-        $user->fill(['name'=>$r->name,'email'=>$r->email,'points'=>$r->points]);
+        $user->fill(['name'=>$r->name,'email'=>$r->email,'points'=>$r->points,'grade'=>$r->grade ?: null]);
         if ($r->filled('password')) $user->password = Hash::make($r->password);
         $user->save();
         return redirect()->route('admin.users.index')->with('success','Gespeichert.');

app/Http/Controllers/Child/LearnController.php

@@ -22,14 +22,24 @@ class LearnController extends Controller {
         $answeredToday = QuestionAttempt::where('user_id',$user->id)
             ->whereDate('created_at', today())
             ->pluck('question_id');
+        $grade    = $user->grade;
         $question = $subject->activeQuestions()
             ->whereNotIn('id', $answeredToday)
+            ->where(function($q) use ($grade) {
+                $q->whereNull('grade');
+                if ($grade) $q->orWhere('grade', $grade);
+            })
             ->with('answerOptions')
             ->inRandomOrder()
             ->first();
         // Falls alle beantwortet: ganz random
         if (!$question) {
-            $question = $subject->activeQuestions()->with('answerOptions')->inRandomOrder()->first();
+            $question = $subject->activeQuestions()
+                ->where(function($q) use ($grade) {
+                    $q->whereNull('grade');
+                    if ($grade) $q->orWhere('grade', $grade);
+                })
+                ->with('answerOptions')->inRandomOrder()->first();
         }
         if (!$question) {
             return redirect()->route('learn.subjects')->with('info','Noch keine Fragen für dieses Fach.');

app/Http/Controllers/Child/QuizController.php

@@ -8,7 +8,12 @@ class QuizController extends Controller {
 
     public function index() {
         $subjects = Subject::all()->keyBy('id');
+        $grade    = auth()->user()->grade;
         $quizzes  = Quiz::with('subject')->where('active',true)
+            ->where(function($q) use ($grade) {
+                $q->whereNull('grade');
+                if ($grade) $q->orWhere('grade', $grade);
+            })
             ->withCount('questions')->get()->groupBy('subject_id');
         $bestScores = QuizAttempt::where('user_id',auth()->id())
             ->where('status','completed')

app/Models/User.php

@@ -5,7 +5,7 @@ use Illuminate\Foundation\Auth\User as Authenticatable;
 use Illuminate\Notifications\Notifiable;
 class User extends Authenticatable {
     use HasFactory, Notifiable;
-    protected $fillable = ['name','email','password','role','points'];
+    protected $fillable = ['name','email','password','role','points','grade'];
     protected $hidden = ['password','remember_token'];
     protected $casts = ['email_verified_at' => 'datetime', 'password' => 'hashed'];
 

database/migrations/2026_05_06_000000_add_grade_to_users_quizzes_questions.php

@@ -0,0 +1,16 @@
+<?php
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+return new class extends Migration {
+    public function up(): void {
+        Schema::table('users',     fn(Blueprint $t) => $t->unsignedTinyInteger('grade')->nullable()->after('role'));
+        Schema::table('quizzes',   fn(Blueprint $t) => $t->unsignedTinyInteger('grade')->nullable()->after('active'));
+        Schema::table('questions', fn(Blueprint $t) => $t->unsignedTinyInteger('grade')->nullable()->after('active'));
+    }
+    public function down(): void {
+        Schema::table('users',     fn(Blueprint $t) => $t->dropColumn('grade'));
+        Schema::table('quizzes',   fn(Blueprint $t) => $t->dropColumn('grade'));
+        Schema::table('questions', fn(Blueprint $t) => $t->dropColumn('grade'));
+    }
+};

resources/views/admin/questions/index.blade.php

@@ -67,6 +67,7 @@
     <thead class="bg-slate-50 border-b border-slate-200">
       <tr>
         <th class="text-left px-4 py-3 font-medium text-slate-600">Frage</th>
+        <th class="text-center px-4 py-3 font-medium text-slate-600">Klasse</th>
         <th class="text-center px-4 py-3 font-medium text-slate-600">Schwierigkeit</th>
         <th class="text-center px-4 py-3 font-medium text-slate-600 hidden sm:table-cell">Aktiv</th>
         <th class="px-4 py-3"></th>
@@ -78,6 +79,7 @@
       <td class="px-4 py-3 text-slate-700 max-w-xs">
         <span class="line-clamp-2">{{ $q->question_text }}</span>
       </td>
+      <td class="px-4 py-3 text-center text-xs text-slate-500">{{ $q->grade ? "Kl.".$q->grade : "–" }}</td>
       <td class="px-4 py-3 text-center">{{ $q->difficultyStars() }}</td>
       <td class="px-4 py-3 text-center hidden sm:table-cell">{{ $q->active ? '✅' : '⏸️' }}</td>
       <td class="px-4 py-3 text-right whitespace-nowrap">

resources/views/admin/quizzes/create.blade.php

@@ -21,6 +21,15 @@
         <label class="block text-sm font-medium text-slate-700 mb-1">Beschreibung (optional)</label>
         <textarea name="description" rows="2" class="w-full border border-slate-300 rounded-lg px-3 py-2 text-sm focus:ring-2 focus:ring-violet-500 outline-none">{{ old('description') }}</textarea>
       </div>
+      <div>
+        <label class="block text-sm font-medium text-slate-700 mb-1">Zielklasse <span class="text-slate-400 font-normal">(leer = für alle Kinder)</span></label>
+        <select name="grade" class="w-full border border-slate-300 rounded-lg px-3 py-2 text-sm focus:ring-2 focus:ring-violet-500 outline-none">
+          <option value="">Alle Klassen</option>
+          @for($g=1;$g<=10;$g++)
+          <option value="{{ $g }}" {{ old('grade','')==$g?'selected':'' }}>Klasse {{ $g }}</option>
+          @endfor
+        </select>
+      </div>
       <button type="submit" class="w-full bg-violet-600 hover:bg-violet-700 text-white py-2 rounded-lg font-medium text-sm">Erstellen & Fragen hinzufügen →</button>
     </form>
   </div>

resources/views/admin/quizzes/edit.blade.php

@@ -25,6 +25,15 @@
         <label class="block text-sm font-medium text-slate-700 mb-1">Beschreibung</label>
         <textarea name="description" rows="2" class="w-full border border-slate-300 rounded-lg px-3 py-2 text-sm focus:ring-2 focus:ring-violet-500 outline-none">{{ $quiz->description }}</textarea>
       </div>
+      <div>
+        <label class="block text-sm font-medium text-slate-700 mb-1">Zielklasse <span class="text-slate-400 font-normal">(leer = für alle Kinder)</span></label>
+        <select name="grade" class="w-full border border-slate-300 rounded-lg px-3 py-2 text-sm focus:ring-2 focus:ring-violet-500 outline-none">
+          <option value="">Alle Klassen</option>
+          @for($g=1;$g<=10;$g++)
+          <option value="{{ $g }}" {{ old('grade',$quiz->grade)==$g?'selected':'' }}>Klasse {{ $g }}</option>
+          @endfor
+        </select>
+      </div>
       <div class="flex items-center gap-2">
         <input type="checkbox" name="active" id="active" value="1" {{ $quiz->active?'checked':'' }} class="w-4 h-4 text-violet-600">
         <label for="active" class="text-sm text-slate-700">Quiz aktiv (für Kinder sichtbar)</label>

resources/views/admin/quizzes/index.blade.php

@@ -36,7 +36,9 @@
     @forelse($quizzes as $quiz)
     <tr class="hover:bg-slate-50">
       <td class="px-4 py-3 text-slate-600">{{ $quiz->subject->icon }} {{ $quiz->subject->name }}</td>
-      <td class="px-4 py-3 font-medium text-slate-800">{{ $quiz->title }}</td>
+      <td class="px-4 py-3 font-medium text-slate-800">{{ $quiz->title }}
+        @if($quiz->grade)<span class="ml-2 text-xs bg-indigo-100 text-indigo-700 px-2 py-0.5 rounded-full">Kl.{{ $quiz->grade }}</span>@endif
+      </td>
       <td class="px-4 py-3 text-center">
         <span class="{{ $quiz->questions_count < 10 ? 'text-amber-600' : 'text-green-600' }} font-medium">
           {{ $quiz->questions_count }}/10

resources/views/admin/users/create.blade.php

@@ -22,6 +22,15 @@
         <input name="password" type="password" required class="w-full border border-slate-300 rounded-lg px-3 py-2 text-sm focus:ring-2 focus:ring-violet-500 focus:border-transparent outline-none">
         @error('password')<p class="text-red-500 text-xs mt-1">{{ $message }}</p>@enderror
       </div>
+      <div>
+        <label class="block text-sm font-medium text-slate-700 mb-1">Klasse</label>
+        <select name="grade" class="w-full border border-slate-300 rounded-lg px-3 py-2 text-sm focus:ring-2 focus:ring-violet-500 outline-none">
+          <option value="">– Keine Klasse –</option>
+          @for($g=1;$g<=10;$g++)
+          <option value="{{ $g }}" {{ old('grade','')==$g?'selected':'' }}>Klasse {{ $g }}</option>
+          @endfor
+        </select>
+      </div>
       <button type="submit" class="w-full bg-violet-600 hover:bg-violet-700 text-white py-2 rounded-lg font-medium text-sm">Konto erstellen</button>
     </form>
   </div>

resources/views/admin/users/edit.blade.php

@@ -23,6 +23,15 @@
         <label class="block text-sm font-medium text-slate-700 mb-1">🪙 Münzen</label>
         <input name="points" type="number" min="0" value="{{ old('points',$user->points) }}" required class="w-full border border-slate-300 rounded-lg px-3 py-2 text-sm focus:ring-2 focus:ring-violet-500 outline-none">
       </div>
+      <div>
+        <label class="block text-sm font-medium text-slate-700 mb-1">Klasse</label>
+        <select name="grade" class="w-full border border-slate-300 rounded-lg px-3 py-2 text-sm focus:ring-2 focus:ring-violet-500 outline-none">
+          <option value="">– Keine Klasse –</option>
+          @for($g=1;$g<=10;$g++)
+          <option value="{{ $g }}" {{ old('grade',$user->grade)==$g?'selected':'' }}>Klasse {{ $g }}</option>
+          @endfor
+        </select>
+      </div>
       <button type="submit" class="w-full bg-violet-600 hover:bg-violet-700 text-white py-2 rounded-lg font-medium text-sm">Speichern</button>
     </form>
   </div>

resources/views/admin/users/index.blade.php

@@ -11,6 +11,7 @@
       <tr>
         <th class="text-left px-4 py-3 font-medium text-slate-600">Name</th>
         <th class="text-left px-4 py-3 font-medium text-slate-600">E-Mail</th>
+        <th class="text-center px-4 py-3 font-medium text-slate-600">Klasse</th>
         <th class="text-right px-4 py-3 font-medium text-slate-600">🪙 Münzen</th>
         <th class="text-right px-4 py-3 font-medium text-slate-600">Antworten</th>
         <th class="px-4 py-3"></th>
@@ -21,6 +22,7 @@
       <tr class="hover:bg-slate-50">
         <td class="px-4 py-3 font-medium text-slate-800">{{ $u->name }}</td>
         <td class="px-4 py-3 text-slate-500">{{ $u->email }}</td>
+        <td class="px-4 py-3 text-center text-sm text-slate-500">{{ $u->grade ? "Klasse ".$u->grade : "–" }}</td>
       <td class="px-4 py-3 text-right font-bold text-amber-600">{{ $u->points }}</td>
         <td class="px-4 py-3 text-right text-slate-500">{{ $u->attempts_count }}</td>
         <td class="px-4 py-3 text-right whitespace-nowrap">