fix(matchmaking): deploy signal targets only the deploying player

EnterMatchmakingMatch broadcast OnSquadMatchmakingSuccess to Clients.All,
so one player deploying pulled every connected player into the match.
Map each player to their SignalR connection (GetSignalRConnection tags the
URL with uid; CycleHub records it via a SignalRConnectionRegistry) and
send the deploy signal only to that connection (broadcast fallback if
unmapped). Also enable m_automaticImportPlatformFriends (Steam friends).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/Prospect.Server.Api/Services/CloudScript/Functions/GetSignalRConnection.cs

@@ -2,6 +2,7 @@ using System.Net;
 using System.Net.Sockets;
 using Microsoft.Extensions.Options;
 using Prospect.Server.Api.Config;
+using Prospect.Server.Api.Services.Auth.Extensions;
 using Prospect.Server.Api.Services.CloudScript.Models;
 
 namespace Prospect.Server.Api.Services.CloudScript.Functions;
@@ -43,7 +44,13 @@ public class GetSignalRConnection : ICloudScriptFunction<FYGetSignalRConnection,
             catch { /* keep the configured URL on any parsing issue */ }
         }
 
-        _logger.LogInformation("GetSignalRConnection: remoteIp={Remote} lan={Lan} -> {Url}", remote, lan, url);
+        // Tag the connection with the player id so the hub can map connection -> user and
+        // target server messages (deploy signal) instead of broadcasting to everyone.
+        var userId = _httpContextAccessor.HttpContext?.User.FindAuthUserId();
+        if (!string.IsNullOrEmpty(userId))
+            url += (url.Contains('?') ? "&" : "?") + "uid=" + Uri.EscapeDataString(userId);
+
+        _logger.LogInformation("GetSignalRConnection: remoteIp={Remote} lan={Lan} uid={Uid} -> {Url}", remote, lan, userId, url);
 
         return Task.FromResult(new FYGetSignalRConnectionResult
         {