Request resync instead of crashing on missing Shardok results (#4622)

* Request resync instead of crashing on missing Shardok results

When HandleUpdates detects missing results (expected > existing + new),
likely due to dropped packets on bad network, request a full resync
instead of throwing an exception.

Changes:
- ShardokGameModel.HandleUpdates now returns bool (true=ok, false=need resync)
- EagleGameModel marks game for resync and clears history on mismatch
- CustomBattleHandler clears history and continues on mismatch

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

* Add missing UnityEngine using statement for Debug.Log

Fixes build error: error CS0103: The name 'Debug' does not exist in the current context

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/ConnectionHandler/CustomBattleHandler.cs

@@ -187,9 +187,14 @@ public class CustomBattleHandler : MonoBehaviour, IClientConnectionSubscriber {
                 case GameUpdate.GameUpdateDetailsOneofCase.ShardokActionResultResponse:
                     foreach (var resp in gameUpdate.ShardokActionResultResponse
                                      .ShardokGameResponses) {
-                        _shardokModel.HandleUpdates(
+                        var updatesOk = _shardokModel.HandleUpdates(
                                 resp.ActionResultViews,
                                 resp.NewResultViewCount);
+                        if (!updatesOk) {
+                            // In custom battle mode, just clear and continue
+                            _shardokModel.History.Clear();
+                            continue;
+                        }
                         _shardokModel.HandleAvailableCommands(resp.AvailableCommands);
                     }
 

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Eagle/EagleGameModel.cs

@@ -316,9 +316,17 @@ namespace eagle {
                             }
                         }
 
-                        shardokGameModel.HandleUpdates(
+                        var updatesOk = shardokGameModel.HandleUpdates(
                                 oneResponse.ActionResultViews,
                                 oneResponse.NewResultViewCount);
+
+                        if (!updatesOk) {
+                            // Missing results - mark for resync and clear history
+                            MarkShardokForResync(oneResponse.ShardokGameId);
+                            shardokGameModel.History.Clear();
+                            continue;
+                        }
+
                         shardokGameModel.HandleAvailableCommands(oneResponse.AvailableCommands);
 
                         // Clear resync flag after successfully receiving updates

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Shardok/ShardokGameModel.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using eagle;
 using eagle0;
+using UnityEngine;
 using Net.Eagle0.Shardok.Api;
 using Net.Eagle0.Shardok.Common;
 using UnityGoDiceInterface;
@@ -173,7 +174,10 @@ public class ShardokGameModel {
         return null;
     }
 
-    public void HandleUpdates(
+    /// <summary>
+    /// Returns true if updates were handled successfully, false if a resync is needed.
+    /// </summary>
+    public bool HandleUpdates(
             IEnumerable<ActionResultView> newHistory,
             int expectedNewResultCount) {
         var existingHistoryCount = History.Count();
@@ -182,12 +186,16 @@ public class ShardokGameModel {
             var diff = existingHistoryCount + newHistoryCount - expectedNewResultCount;
             History.RemoveRange(existingHistoryCount - diff, diff);
         } else if (expectedNewResultCount > existingHistoryCount + newHistoryCount) {
-            throw new ArgumentException(
-                    $"Should have {expectedNewResultCount} results but we have {existingHistoryCount + newHistoryCount}");
+            // Missing results - likely due to dropped packets on bad network.
+            // Request a full resync instead of crashing.
+            Debug.Log(
+                    $"ShardokGameModel: Missing results (expected {expectedNewResultCount}, have {existingHistoryCount + newHistoryCount}). Requesting resync.");
+            return false;
         }
         foreach (ActionResultView entry in newHistory) { HandleNewHistoryEntry(entry); }
 
         if (newHistoryCount > 0 && UpdateAction != null) { UpdateAction.Invoke(); }
+        return true;
     }
 
     public void HandleAvailableCommands(AvailableCommands newCommands) {