feat: select text across bullets and delete it like a text editor; Ctrl+Z in tasks; notes and lists without emoji; custom done columns complete tasks

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

frontend/src/lib/api.ts

@@ -953,11 +953,12 @@ export const api = {
 
   async createList(titleOrSpaceId: string, titleOrIcon?: string, iconOrType?: string, listType?: 'shopping' | 'checklist' | 'vacation'): Promise<SharedList> {
     let title = titleOrSpaceId;
-    let icon = titleOrIcon || '🛒';
+    // An empty icon means "no icon"; only a missing one gets the default
+    let icon = titleOrIcon ?? '🛒';
     let type = (iconOrType as any) || 'shopping';
     if (listType !== undefined) {
       title = titleOrIcon || '';
-      icon = iconOrType || '🛒';
+      icon = iconOrType ?? '🛒';
       type = listType;
     }
     const l = await request<SharedList>('/api/v1/lists', {