feat: Vor-/Nachname, geteilte Listen zeigen Eigentuemer

Backend:
- User.first_name / User.last_name (nullable, Auto-Migrate fuegt sie an)
  full_name/display_name als Properties + in to_dict
- TaskList.owner-Relationship ergaenzt (fehlte, daher wurden geteilte
  Listen beim Empfaenger nicht korrekt aufgeloest)
- /auth/me GET + PUT (Profil bearbeiten: Vorname, Nachname, E-Mail)
- /users/search findet jetzt auch nach Vor-/Nachname und liefert
  full_name/display_name mit
- list_tasklists/list_calendars/list_addressbooks liefern
  owner_full_name und owner_display_name

Frontend:
- Sidebars bei Kontakten/Kalender/Aufgaben: "(geteilt von <Voller Name>)"
  mit Fallback auf Username
- User-Search-Popup zeigt vollen Namen neben Username
- SettingsView: Vorname/Nachname/E-Mail bearbeiten

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/api/calendar.py

@@ -109,6 +109,8 @@ def list_calendars():
         if share and share.color:
             d['color'] = share.color
         d['owner_name'] = c.owner.username
+        d['owner_full_name'] = c.owner.full_name
+        d['owner_display_name'] = c.owner.display_name
         result.append(d)
 
     return jsonify(result), 200

backend/app/api/contacts.py

@@ -292,6 +292,8 @@ def list_addressbooks():
         if share and share.color:
             d['color'] = share.color
         d['owner_name'] = b.owner.username
+        d['owner_full_name'] = b.owner.full_name
+        d['owner_display_name'] = b.owner.display_name
         d['contact_count'] = b.contacts.count()
         result.append(d)
 

backend/app/api/tasks.py

@@ -212,7 +212,10 @@ def list_tasklists():
             continue
         d = tl.to_dict()
         d['permission'] = s.permission
-        d['owner_name'] = tl.owner.username if tl.owner else ''
+        owner = tl.owner
+        d['owner_name'] = owner.username if owner else ''
+        d['owner_full_name'] = owner.full_name if owner else ''
+        d['owner_display_name'] = owner.display_name if owner else ''
         d['task_count'] = tl.tasks.count()
         if s.color:
             d['color'] = s.color

backend/app/api/users.py

@@ -281,6 +281,31 @@ def create_invite_link():
 
 # --- User search (for sharing dialogs) ---
 
+@api_bp.route('/auth/me', methods=['GET'])
+@token_required
+def get_me():
+    return jsonify(request.current_user.to_dict(include_email=True)), 200
+
+
+@api_bp.route('/auth/me', methods=['PUT'])
+@token_required
+def update_me():
+    user = request.current_user
+    data = request.get_json() or {}
+    if 'first_name' in data:
+        user.first_name = (data.get('first_name') or '').strip() or None
+    if 'last_name' in data:
+        user.last_name = (data.get('last_name') or '').strip() or None
+    if 'email' in data:
+        email = (data.get('email') or '').strip() or None
+        if email and email != user.email:
+            if User.query.filter(User.email == email, User.id != user.id).first():
+                return jsonify({'error': 'E-Mail ist bereits vergeben'}), 409
+        user.email = email
+    db.session.commit()
+    return jsonify(user.to_dict(include_email=True)), 200
+
+
 @api_bp.route('/users/search', methods=['GET'])
 @token_required
 def search_users():
@@ -289,13 +314,19 @@ def search_users():
     if len(query) < 2:
         return jsonify([]), 200
 
+    like = f'%{query}%'
     users = User.query.filter(
-        User.username.ilike(f'%{query}%'),
+        (User.username.ilike(like)) | (User.first_name.ilike(like)) | (User.last_name.ilike(like)),
         User.id != request.current_user.id,
         User.is_active == True,
     ).limit(10).all()
 
-    return jsonify([{'id': u.id, 'username': u.username} for u in users]), 200
+    return jsonify([{
+        'id': u.id,
+        'username': u.username,
+        'full_name': u.full_name,
+        'display_name': u.display_name,
+    } for u in users]), 200
 
 
 # --- Change password (non-admin, own account) ---

backend/app/models/user.py

@@ -9,6 +9,8 @@ class User(db.Model):
     id = db.Column(db.Integer, primary_key=True)
     username = db.Column(db.String(80), unique=True, nullable=False, index=True)
     email = db.Column(db.String(255), unique=True, nullable=True)
+    first_name = db.Column(db.String(100), nullable=True)
+    last_name = db.Column(db.String(100), nullable=True)
     password_hash = db.Column(db.String(255), nullable=False)
     role = db.Column(db.String(20), default='user', nullable=False)  # 'admin' or 'user'
     master_key_salt = db.Column(db.LargeBinary, nullable=True)  # For password manager
@@ -23,6 +25,7 @@ class User(db.Model):
                             foreign_keys='File.owner_id')
     calendars = db.relationship('Calendar', backref='owner', lazy='dynamic')
     address_books = db.relationship('AddressBook', backref='owner', lazy='dynamic')
+    task_lists = db.relationship('TaskList', backref='owner', lazy='dynamic')
     email_accounts = db.relationship('EmailAccount', backref='user', lazy='dynamic',
                                      order_by='EmailAccount.sort_order')
     password_folders = db.relationship('PasswordFolder', backref='owner', lazy='dynamic')
@@ -33,10 +36,25 @@ class User(db.Model):
     def check_password(self, password):
         return bcrypt.check_password_hash(self.password_hash, password)
 
+    @property
+    def full_name(self) -> str:
+        """Vor- + Nachname zusammengesetzt, sonst Leerstring."""
+        parts = [self.first_name or '', self.last_name or '']
+        return ' '.join(p.strip() for p in parts if p and p.strip())
+
+    @property
+    def display_name(self) -> str:
+        """Voller Name falls vorhanden, sonst Username."""
+        return self.full_name or self.username
+
     def to_dict(self, include_email=False):
         data = {
             'id': self.id,
             'username': self.username,
+            'first_name': self.first_name or '',
+            'last_name': self.last_name or '',
+            'full_name': self.full_name,
+            'display_name': self.display_name,
             'role': self.role,
             'is_active': self.is_active,
             'storage_quota_mb': self.storage_quota_mb,