fix(mobile): sheets above the keyboard, emoji picker, cleaner header

- FormSheet: create dialogs (task list, shopping list, folder) as bottom
  sheet right above the on-screen keyboard (visualViewport), large fields;
  centred or anchored dialog on desktop
- Emoji picker: category icons keep their sprite size (no doubled icons,
  round highlight), one 'Zuletzt verwendet' (library category, German
  names), sheet and picker height follow the keyboard
- Mobile header no longer repeats the current section next to the logo

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/features/lists/SharedListsView.tsx

@@ -15,6 +15,7 @@ import { api, buildWebSocketURL, triggerHaptic, createRealtimeConnection, Realti
 import { UnifiedShareModal } from '../../components/UnifiedShareModal';
 import { AvatarStack, AvatarPerson } from '../../components/AvatarStack';
 import { CountBadge } from '../../components/CountBadge';
+import { FormSheet } from '../../components/FormSheet';
 import { useMobileActions } from '../../context/MobileActionContext';
 
 interface SharedListsViewProps {
@@ -1017,61 +1018,35 @@ export const SharedListsView: React.FC<SharedListsViewProps> = ({ onRefreshGloba
       </div>
 
       {showNewListModal && (
-        <div className="fixed inset-0 !m-0 modal-overlay z-50 flex items-center justify-center p-4">
-          <div className="w-full max-w-sm panel-surface shadow-panel p-4 space-y-3">
-            <div className="flex items-center justify-between border-b border-border pb-2">
-              <h3 className="text-sm font-semibold text-main flex items-center gap-1.5">
-                <ShoppingCart className="w-4 h-4 text-accent" />
-                <span>Neue Einkaufsliste erstellen</span>
-              </h3>
-              <button
-                type="button"
-                onClick={() => setShowNewListModal(false)}
-                className="text-muted hover:text-main"
-              >
-                <X className="w-4 h-4" />
-              </button>
+        <FormSheet
+          title="Neue Einkaufsliste erstellen"
+          icon={<ShoppingCart className="w-4 h-4 text-accent" />}
+          onClose={() => setShowNewListModal(false)}
+          onSubmit={handleCreateList}
+        >
+            <div>
+              <label className="block text-xs text-muted mb-1">Titel der Liste</label>
+              <div className="flex items-center gap-1.5">
+                <input
+                  type="text"
+                  value={newListIcon}
+                  onChange={(e) => setNewListIcon(e.target.value)}
+                  maxLength={2}
+                  className="w-12 sm:w-10 h-11 sm:h-8 text-center input-field text-base sm:text-sm"
+                  title="Icon (Emoji)"
+                />
+                <input
+                  type="text"
+                  value={newListTitle}
+                  onChange={(e) => setNewListTitle(e.target.value)}
+                  placeholder="z.B. Supermarkt, Baumarkt, Drogerie"
+                  autoFocus
+                  required
+                  className="flex-1 min-w-0 h-11 sm:h-8 input-field px-2.5 text-base sm:text-xs"
+                />
+              </div>
             </div>
-
-            <form onSubmit={handleCreateList} className="space-y-3">
-              <div>
-                <label className="block text-xs text-muted mb-1">Titel der Liste</label>
-                <div className="flex items-center gap-1.5">
-                  <input
-                    type="text"
-                    value={newListIcon}
-                    onChange={(e) => setNewListIcon(e.target.value)}
-                    maxLength={2}
-                    className="w-10 h-8 text-center input-field text-sm"
-                    title="Icon (Emoji)"
-                  />
-                  <input
-                    type="text"
-                    value={newListTitle}
-                    onChange={(e) => setNewListTitle(e.target.value)}
-                    placeholder="z.B. Supermarkt, Baumarkt, Drogerie"
-                    autoFocus
-                    required
-                    className="flex-1 h-8 input-field px-2.5 text-xs"
-                  />
-                </div>
-              </div>
-
-              <div className="flex items-center justify-end gap-2 pt-2 border-t border-border">
-                <button
-                  type="button"
-                  onClick={() => setShowNewListModal(false)}
-                  className="btn-action h-7 px-3 text-xs"
-                >
-                  Abbrechen
-                </button>
-                <button type="submit" className="btn-primary h-7 px-3 text-xs">
-                  Erstellen
-                </button>
-              </div>
-            </form>
-          </div>
-        </div>
+        </FormSheet>
       )}
 
       {/* Active Shared List View */}