Add email templates, page layouts, and shop themes (template system)

- E-Mail-Templates: DB-gespeicherte HTML-Templates mit {{placeholder}}-System,
  Admin-UI zum Bearbeiten von Betreff und Body, alle 4 Mailables aktualisiert
- Seiten-Layouts: 4 Layouts für CMS-Seiten (Standard, Sidebar, Volle Breite, Landing),
  Layout-Auswahl im Admin-Formular
- Shop-Themes: 5 Farbthemen via CSS-Variablen, Picker in Einstellungen
- Deployment: EmailTemplateSeeder wird automatisch beim Deploy ausgeführt

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

resources/views/admin/email-templates/edit.blade.php

@@ -0,0 +1,48 @@
+@extends('layouts.admin')
+@section('title', 'E-Mail-Template: ' . $template->label)
+@section('content')
+<div class="flex items-center gap-3 mb-6">
+    <a href="{{ route('admin.email-templates.index') }}" class="text-gray-400 hover:text-gray-600">← Zurück</a>
+    <h2 class="text-xl font-bold">{{ $template->label }}</h2>
+</div>
+
+@if(session('success'))
+    <div class="bg-green-100 border border-green-300 text-green-800 px-4 py-3 rounded mb-4">{{ session('success') }}</div>
+@endif
+
+<form method="POST" action="{{ route('admin.email-templates.update', $template) }}" class="space-y-5">
+    @csrf @method('PUT')
+
+    <div class="bg-white rounded shadow p-6 space-y-4">
+        <div>
+            <label class="block text-sm font-medium mb-1">Betreff</label>
+            <input type="text" name="subject" value="{{ old('subject', $template->subject) }}"
+                   class="w-full border rounded px-3 py-2 text-sm @error('subject') border-red-500 @enderror">
+            @error('subject')<p class="text-red-600 text-xs mt-1">{{ $message }}</p>@enderror
+        </div>
+
+        <div>
+            <label class="block text-sm font-medium mb-1">HTML-Inhalt</label>
+            <textarea name="body" rows="24"
+                      class="w-full border rounded px-3 py-2 text-sm font-mono @error('body') border-red-500 @enderror">{{ old('body', $template->body) }}</textarea>
+            @error('body')<p class="text-red-600 text-xs mt-1">{{ $message }}</p>@enderror
+        </div>
+    </div>
+
+    @if($template->variables)
+    <div class="bg-blue-50 border border-blue-200 rounded p-4 text-sm">
+        <p class="font-medium text-blue-800 mb-2">Verfügbare Platzhalter:</p>
+        <div class="flex flex-wrap gap-2">
+            @foreach($template->variables as $var)
+            <code class="bg-blue-100 text-blue-700 px-2 py-0.5 rounded text-xs">{{"{{"}}{{ $var }}{{"}}"}}</code>
+            @endforeach
+        </div>
+    </div>
+    @endif
+
+    <div class="flex gap-3">
+        <button type="submit" class="bg-blue-600 text-white px-6 py-2 rounded hover:bg-blue-700">Speichern</button>
+        <a href="{{ route('admin.email-templates.index') }}" class="border px-6 py-2 rounded hover:bg-gray-50 text-sm">Abbrechen</a>
+    </div>
+</form>
+@endsection

resources/views/admin/email-templates/index.blade.php

@@ -0,0 +1,43 @@
+@extends('layouts.admin')
+@section('title', 'E-Mail-Templates')
+@section('content')
+<div class="flex items-center justify-between mb-6">
+    <h2 class="text-xl font-bold">E-Mail-Templates</h2>
+</div>
+
+@if(session('success'))
+    <div class="bg-green-100 border border-green-300 text-green-800 px-4 py-3 rounded mb-4">{{ session('success') }}</div>
+@endif
+
+@if($templates->isEmpty())
+    <div class="bg-yellow-50 border border-yellow-200 text-yellow-800 px-4 py-3 rounded">
+        Keine Templates gefunden. Bitte führen Sie <code>php artisan db:seed --class=EmailTemplateSeeder</code> aus.
+    </div>
+@else
+<div class="bg-white rounded shadow overflow-hidden">
+    <table class="w-full text-sm">
+        <thead class="bg-gray-50 text-gray-600 uppercase text-xs">
+            <tr>
+                <th class="px-4 py-3 text-left">Template</th>
+                <th class="px-4 py-3 text-left">Betreff</th>
+                <th class="px-4 py-3 text-left">Zuletzt geändert</th>
+                <th class="px-4 py-3"></th>
+            </tr>
+        </thead>
+        <tbody class="divide-y divide-gray-100">
+            @foreach($templates as $tpl)
+            <tr class="hover:bg-gray-50">
+                <td class="px-4 py-3 font-medium">{{ $tpl->label }}</td>
+                <td class="px-4 py-3 text-gray-600 max-w-xs truncate">{{ $tpl->subject }}</td>
+                <td class="px-4 py-3 text-gray-500">{{ $tpl->updated_at->format('d.m.Y H:i') }}</td>
+                <td class="px-4 py-3 text-right">
+                    <a href="{{ route('admin.email-templates.edit', $tpl) }}"
+                       class="text-blue-600 hover:underline">Bearbeiten</a>
+                </td>
+            </tr>
+            @endforeach
+        </tbody>
+    </table>
+</div>
+@endif
+@endsection

resources/views/admin/pages/form.blade.php

@@ -152,6 +152,14 @@
                        class="w-full border rounded px-3 py-2 text-sm" min="0">
                 <p class="text-xs text-gray-400 mt-1">Niedrigere Zahl = weiter links</p>
             </div>
+            <div>
+                <label class="block text-sm font-medium mb-1">Seiten-Layout</label>
+                <select name="layout" class="w-full border rounded px-3 py-2 text-sm">
+                    @foreach(['default'=>'Standard (zentriert)','sidebar'=>'Mit Sidebar','full'=>'Volle Breite','landing'=>'Landing Page (ohne Header/Footer)'] as $val => $label)
+                    <option value="{{ $val }}" {{ old('layout', $page->layout ?? 'default') === $val ? 'selected' : '' }}>{{ $label }}</option>
+                    @endforeach
+                </select>
+            </div>
         </div>
     </div>