feat(pipeline): add numeric comparison mode to sort step

src/pipeline/steps/transform.ts

@@ -60,9 +60,7 @@ export async function stepSort(_page: IPage | null, params: unknown, data: unkno
   return [...data].sort((a, b) => {
     const left = isRecord(a) ? a[key] : undefined;
     const right = isRecord(b) ? b[key] : undefined;
-    const va = left ?? '';
-    const vb = right ?? '';
-    const cmp = va < vb ? -1 : va > vb ? 1 : 0;
+    const cmp = String(left ?? '').localeCompare(String(right ?? ''), undefined, { numeric: true });
     return reverse ? -cmp : cmp;
   });
 }

src/pipeline/transform.test.ts

@@ -101,6 +101,26 @@ describe('stepSort', () => {
     await stepSort(null, 'score', SAMPLE_DATA, {});
     expect(SAMPLE_DATA).toEqual(original);
   });
+
+  it('sorts string-encoded numbers naturally by default', async () => {
+    const data = [
+      { name: 'A', volume: '99' },
+      { name: 'B', volume: '1000' },
+      { name: 'C', volume: '250' },
+    ];
+    const result = await stepSort(null, { by: 'volume', order: 'desc' }, data, {});
+    expect((result as typeof data).map((r) => r.name)).toEqual(['B', 'C', 'A']);
+  });
+
+  it('handles missing fields gracefully', async () => {
+    const data = [
+      { name: 'A', value: '10' },
+      { name: 'B' },
+      { name: 'C', value: '5' },
+    ];
+    const result = await stepSort(null, { by: 'value', order: 'asc' }, data, {});
+    expect((result as typeof data).map((r) => r.name)).toEqual(['B', 'C', 'A']);
+  });
 });
 
 describe('stepLimit', () => {