Fix black screen: subscribe to Media Gateway streams via live mode

src/lib/agora-config.ts

@@ -20,7 +20,7 @@ export class AgoraClient {
 
   constructor(config: AgoraConfig) {
     this.config = {
-      mode: 'rtc',
+      mode: 'live',
       codec: 'vp8',
       ...config
     };
@@ -31,10 +31,12 @@ export class AgoraClient {
 
     const AgoraRTC = (await import('agora-rtc-sdk-ng')).default;
 
-    // Force RTC mode and VP8 codec for video streaming
+    // Use live-broadcast mode so the client can subscribe to streams injected
+    // by Agora Media Gateway (RTMP/SRT ingest), which join the channel as
+    // live-broadcast hosts. An rtc/communication-mode client cannot see them.
     this.client = AgoraRTC.createClient({
-      mode: 'rtc',
-      codec: 'vp8'
+      mode: this.config.mode || 'live',
+      codec: this.config.codec || 'vp8'
     });
 
     this.setupEventListeners();
@@ -205,11 +207,24 @@ export class AgoraClient {
         }
       }
 
+      // In live-broadcast mode every client must declare its role before joining:
+      // publishers join as hosts, viewers as audience so they subscribe to hosts.
+      await this.client.setClientRole(role === 'publisher' ? 'host' : 'audience');
+
+      // Coerce a numeric uid to a Number. The cameras are injected by Media
+      // Gateway with integer uids; joining with a *string* uid puts us in
+      // user-account mode, where we don't receive the host's published stream
+      // (black screen). Keep genuinely non-numeric accounts as-is.
+      const joinUid =
+        this.config.uid === undefined || this.config.uid === null || this.config.uid === ''
+          ? null
+          : (isNaN(Number(this.config.uid)) ? this.config.uid : Number(this.config.uid));
+
       const uid = await this.client.join(
         this.config.appId.trim(),
         this.config.channel.trim(),
         token,
-        this.config.uid || null
+        joinUid
       );
 
       console.log(`Joined channel as ${role} with uid:`, uid);