Add Geschichte (History) wiki-style feature with reorganized navigation

🆕 NEW FEATURES:
- Wiki-style Geschichte (History) section with rich text editor
- Image upload support for history pages
- Quill.js rich text editor with formatting options
- Slug-based URLs for SEO-friendly history pages
- Image galleries with descriptions and alt-text support

🔧 MODELS:
- GeschichteSeite: Main history pages with rich content
- GeschichteBild: Image attachments for history pages
- Auto-generated slugs, sorting, publishing controls

📝 TEMPLATES:
- geschichte/liste.html: Card-based overview of all history pages
- geschichte/detail.html: Full page view with image gallery
- geschichte/form.html: Rich text editor for creating/editing pages
- geschichte/bild_form.html: Image upload interface

🎨 UI IMPROVEMENTS:
- Reorganized navigation menu into logical groups:
  * Menschen & Finanzen (People & Finance)
  * Immobilien & Land (Real Estate & Land)
  * Verwaltung (Administration)
  * Geschichte (History)
- More compact menu design saving horizontal space
- Better grouping with dropdown headers

🛠️ TECHNICAL:
- Rich text editor with Quill.js integration
- Image upload with validation and optimization
- Permission-based access controls
- Responsive design for all screen sizes
- Proper breadcrumb navigation
- Auto-slug generation from titles

app/stiftung/forms.py

@@ -1603,3 +1603,92 @@ class BackupTokenRegenerateForm(forms.Form):
         label='Passwort',
         help_text='Geben Sie Ihr Passwort ein, um neue Backup-Codes zu generieren'
     )
+
+
+class GeschichteSeiteForm(forms.ModelForm):
+    """Form for creating and editing history pages"""
+    
+    class Meta:
+        from .models import GeschichteSeite
+        model = GeschichteSeite
+        fields = ['titel', 'slug', 'inhalt', 'ist_veroeffentlicht', 'sortierung']
+        widgets = {
+            'titel': forms.TextInput(attrs={
+                'class': 'form-control',
+                'placeholder': 'z.B. Gründung der Stiftung'
+            }),
+            'slug': forms.TextInput(attrs={
+                'class': 'form-control',
+                'placeholder': 'z.B. gruendung-der-stiftung'
+            }),
+            'inhalt': forms.Textarea(attrs={
+                'class': 'form-control rich-text-editor',
+                'rows': 20,
+                'placeholder': 'Schreiben Sie hier den Inhalt der Geschichtsseite...'
+            }),
+            'ist_veroeffentlicht': forms.CheckboxInput(attrs={
+                'class': 'form-check-input'
+            }),
+            'sortierung': forms.NumberInput(attrs={
+                'class': 'form-control',
+                'min': 0
+            })
+        }
+        help_texts = {
+            'slug': 'URL-freundliche Version des Titels (nur Buchstaben, Zahlen und Bindestriche)',
+            'inhalt': 'Unterstützt Rich-Text-Formatierung, Bilder und Videos',
+            'sortierung': 'Niedrigere Zahlen erscheinen zuerst in der Navigation'
+        }
+    
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        # Auto-generate slug from title if not provided
+        if not self.instance.pk:
+            self.fields['slug'].required = False
+    
+    def clean_slug(self):
+        slug = self.cleaned_data.get('slug')
+        titel = self.cleaned_data.get('titel')
+        
+        if not slug and titel:
+            # Auto-generate slug from title
+            from django.utils.text import slugify
+            slug = slugify(titel)
+        
+        return slug
+
+
+class GeschichteBildForm(forms.ModelForm):
+    """Form for uploading images to history pages"""
+    
+    class Meta:
+        from .models import GeschichteBild
+        model = GeschichteBild
+        fields = ['titel', 'bild', 'beschreibung', 'alt_text', 'sortierung']
+        widgets = {
+            'titel': forms.TextInput(attrs={
+                'class': 'form-control',
+                'placeholder': 'z.B. Gründungsurkunde 1895'
+            }),
+            'bild': forms.ClearableFileInput(attrs={
+                'class': 'form-control'
+            }),
+            'beschreibung': forms.Textarea(attrs={
+                'class': 'form-control',
+                'rows': 3,
+                'placeholder': 'Beschreibung des Bildes...'
+            }),
+            'alt_text': forms.TextInput(attrs={
+                'class': 'form-control',
+                'placeholder': 'Alternativtext für Bildschirmleser'
+            }),
+            'sortierung': forms.NumberInput(attrs={
+                'class': 'form-control',
+                'min': 0
+            })
+        }
+        help_texts = {
+            'bild': 'Unterstützte Formate: JPG, PNG, GIF (max. 10MB)',
+            'alt_text': 'Wichtig für Barrierefreiheit',
+            'sortierung': 'Reihenfolge in der Bildergalerie'
+        }