feat(web): restore legacy channel editor

apps/web_v1/scripts/visual-check.mjs

@@ -229,6 +229,8 @@ for (const channel of [
       foundPage: Boolean(pageNode),
       heading,
       activeChannel,
+      inputCount: pageNode?.querySelectorAll('input, textarea').length ?? 0,
+      hasSaveChannel: [...(pageNode?.querySelectorAll('button') ?? [])].some((button) => button.textContent?.includes('保存频道')),
     }
   }, channel))
 }
@@ -403,6 +405,9 @@ for (const check of channelPageChecks) {
   if (!check.activeChannel.includes(check.label)) {
     failures.push(`expected ${check.label} sidebar button to stay active, got ${JSON.stringify(check.activeChannel)}`)
   }
+  if (check.label === '新建频道' && (check.inputCount < 4 || !check.hasSaveChannel)) {
+    failures.push(`expected legacy new channel editor, got inputs=${check.inputCount}, save=${check.hasSaveChannel}`)
+  }
 }
 
 if (failures.length) {