added offers list to api

RelayServer/Endpoints/RtcEndpoints.cs

@@ -24,6 +24,12 @@ public static class RtcEndpoints
             await rtcCallService.WriteOfferAsync(request.ChannelId, request.Username, request.Sdp);
             return Results.Ok();
         });
+        // List all offers.
+        app.MapGet("/api/rtc/offers", async (RtcCallService rtcCallService) =>
+        {
+            return Results.Ok(await rtcCallService.GetOffersAsync());
+
+        });
 
         // Return whether the specified channel currently has an active call.
         app.MapGet("/api/rtc/active/{channelId}", async (string channelId, RtcCallService rtcCallService) =>
@@ -32,7 +38,7 @@ public static class RtcEndpoints
         });
 
         // Return the latest stored SDP offer for the specified channel.
-        app.MapGet("/api/rtc/offer/{channelId}", async (string channelId, RtcCallService rtcCallService) =>
+        app.MapGet("/api/rtc/offers/{channelId}", async (string channelId, RtcCallService rtcCallService) =>
         {
             var offer = await rtcCallService.GetOfferAsync(channelId);
             return offer is null ? Results.NotFound() : Results.Ok(offer);