fix: paginate getAllSyncedRows to fetch all products beyond the 1000 row Supabase cap

With 1005+ products, the old query returned only the top 1000 by updated_at.
Items edited long ago (like 51016DE) were silently missing from syncedData,
so the merge never applied their saved edits. Now paginate by product_id
until we exhaust the table.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/App.tsx

@@ -134,9 +134,6 @@ export default function App() {
           
           console.log('Fetching synced data from Supabase...');
           const syncedData = await getAllSyncedRows();
-          // TEMP DIAG
-          const d = syncedData['51016DE'];
-          console.log('[DIAG v2] 51016DE:', d ? `status=${d.status} len=${d.data?.length} [103]=${JSON.stringify(d.data?.[103])}` : 'NOT FOUND');
           
           // Extend headers with virtual columns if the Excel is shorter than the saved data.
           // COLUMNS hardcoded indices (PRODUCT_TYPE=103, ITEM_TO_LOGISTIC=104, etc.) are used