Add getYouTubeBroadcastStatus helper

Query YouTube liveBroadcasts API to get lifecycle status (created,
ready, testing, live, complete, revoked) for a given broadcast ID.

src/services/youtube.service.ts

@@ -202,6 +202,24 @@ export async function createYouTubeBroadcast(
   };
 }
 
+export async function getYouTubeBroadcastStatus(
+  accessToken: string,
+  broadcastId: string,
+): Promise<string | null> {
+  const res = await fetch(
+    `https://www.googleapis.com/youtube/v3/liveBroadcasts?part=status&id=${broadcastId}`,
+    {
+      headers: { Authorization: `Bearer ${accessToken}` },
+    },
+  );
+  if (!res.ok) return null;
+  const data = (await res.json()) as any;
+  const items = data.items ?? [];
+  if (items.length === 0) return null;
+  // lifeCycleStatus: created, ready, testing, live, complete, revoked
+  return items[0].status?.lifeCycleStatus ?? null;
+}
+
 export async function transitionYouTubeBroadcast(
   accessToken: string,
   broadcastId: string,