feat(api): enhance peer session tracking and error handling

- Added `PollError` field to `peerSessionOnSpeaker` and `liveSpeakerPoll` types to capture polling errors for speakers.
- Updated `matchPeerOnSpeakers` function to handle polling errors and adjust session state reporting.
- Modified frontend components to display polling error messages alongside session states, improving user visibility into peer connection statuses.
- Enhanced API response structure to include live speaker polling information, facilitating better monitoring of speaker health.

internal/httpapi/routes.go

@@ -294,7 +294,10 @@ func (s *Server) handleListPeers(w http.ResponseWriter, r *http.Request) {
 		items = append(items, row)
 	}
 	writeJSON(w, http.StatusOK, map[string]any{
-		"items": items, "next_cursor": strPtrOrNull(next), "has_more": more,
+		"items":             items,
+		"next_cursor":       strPtrOrNull(next),
+		"has_more":          more,
+		"live_speaker_poll": liveSpeakerPollJSON(liveViews),
 	})
 }