fix(lists): add items offline via the outbox; recognisable input field

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

frontend/src/lib/api.ts

@@ -52,6 +52,9 @@ import {
   clearOfflineData,
   enqueue,
   flushOutbox,
+  dropQueued,
+  updateQueued,
+  OFFLINE_ITEM_PREFIX,
 } from './offline';
 
 const TOKEN_STORAGE_KEY = 'mindsift_jwt_token';
@@ -961,13 +964,32 @@ export const api = {
   },
 
   async createListItem(listId: string, content: string, category = '', quantity = ''): Promise<ListItem> {
-    return request<ListItem>(`/api/v1/lists/${listId}/items`, {
-      method: 'POST',
-      body: JSON.stringify({ content, category, quantity }),
-    });
+    const path = `/api/v1/lists/${listId}/items`;
+    try {
+      return await request<ListItem>(path, { method: 'POST', body: JSON.stringify({ content, category, quantity }) });
+    } catch (err) {
+      if (!(err instanceof OfflineError)) throw err;
+      // Kept in the outbox and sent when the connection is back; until then a stand-in in the list
+      const entry = enqueue('POST', path, { content, category, quantity });
+      return {
+        id: OFFLINE_ITEM_PREFIX + entry.id,
+        listId,
+        content,
+        category,
+        quantity,
+        isCompleted: false,
+        sortOrder: 0,
+        createdAt: entry.createdAt,
+      } as ListItem;
+    }
   },
 
   async toggleListItem(listId: string, itemId: string, isCompleted?: boolean): Promise<ListItem> {
+    // Added offline and checked off before it was sent: nothing left to send
+    if (itemId.startsWith(OFFLINE_ITEM_PREFIX) && isCompleted) {
+      dropQueued(itemId.slice(OFFLINE_ITEM_PREFIX.length));
+      return { id: itemId, listId, isCompleted: true } as ListItem;
+    }
     try {
       return await request<ListItem>(`/api/v1/lists/${listId}/items/${itemId}`, {
         method: 'PATCH',
@@ -985,6 +1007,10 @@ export const api = {
     itemId: string,
     payload: { content?: string; category?: string; quantity?: string }
   ): Promise<ListItem> {
+    if (itemId.startsWith(OFFLINE_ITEM_PREFIX)) {
+      updateQueued(itemId.slice(OFFLINE_ITEM_PREFIX.length), payload);
+      return { id: itemId, listId, ...payload } as ListItem;
+    }
     return request<ListItem>(`/api/v1/lists/${listId}/items/${itemId}`, {
       method: 'PUT',
       body: JSON.stringify(payload),
@@ -992,6 +1018,10 @@ export const api = {
   },
 
   async deleteListItem(listId: string, itemId: string): Promise<void> {
+    if (itemId.startsWith(OFFLINE_ITEM_PREFIX)) {
+      dropQueued(itemId.slice(OFFLINE_ITEM_PREFIX.length));
+      return;
+    }
     await request(`/api/v1/lists/${listId}/items/${itemId}`, { method: 'DELETE' });
   },