Query collaboration capabilities

src/App.svelte

@@ -149,6 +149,7 @@
   let collaboratorSearchTimer: number | undefined;
   let sharedChatSession: { session_id: string; host_broadcaster_id: string; participants: Array<{ broadcaster_id: string }> } | null = null;
   let collaborationSettings: { is_moderator_send_live_enabled: boolean; slot_count: number; is_browser_source_audio_enabled: boolean; group_layout: string; browser_source_token: string } | null = null;
+  let collaborationCapabilities: { guest_star_available: boolean; guest_star_reason?: string | null; shared_chat_available: boolean; shared_chat_reason?: string | null } | null = null;
   let oauthLink = '';
   let oauthIdentity: 'streamer' | 'bot' = 'streamer';
   let oauthBusy = false;
@@ -492,6 +493,8 @@
 
   async function loadCollaboration() {
     try {
+      const capabilities = await fetch(`${serverAddress}/api/v1/twitch/collaboration/capabilities`, { headers: { authorization: `Bearer ${sessionToken}` } });
+      if (capabilities.ok) collaborationCapabilities = await capabilities.json();
       const response = await fetch(`${serverAddress}/api/v1/twitch/collaboration/session`, { headers: { authorization: `Bearer ${sessionToken}` } });
       if (!response.ok) return;
       collaborationSession = await response.json();
@@ -507,6 +510,7 @@
       collaborationSession = null;
       sharedChatSession = null;
       collaborationSettings = null;
+      collaborationCapabilities = null;
     }
   }