Add BattleResetResponse proto messages (#6534)

* Add BattleResetResponse proto messages for tutorial battle reset

Add BattleResetResponse to the internal Shardok interface (oneof case 4
in GameStatusResponse) and ShardokBattleResetResponse to the client-facing
Eagle API (oneof case 8 in GameUpdate). These signal that a tutorial battle
should reset after the defender loses.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add no-op handler for BattleResetResponse in exhaustive match

Prevents -Werror build failure from non-exhaustive pattern match
after adding the new oneof case. Full handling in follow-up PR.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/main/protobuf/net/eagle0/common/shardok_internal_interface.proto

@@ -55,12 +55,15 @@ message PlacementCommandsRequest {
     GameSetupInfo game_setup_info = 6;
 }
 
+message BattleResetResponse {}
+
 message GameStatusResponse {
     string game_id = 1;
 
     oneof Specific {
         GameOverResponse game_over_response = 2;
         GameUpdateResponse game_update_response = 3;
+        BattleResetResponse battle_reset_response = 4;
     }
 }
 

src/main/protobuf/net/eagle0/eagle/api/eagle.proto

@@ -166,6 +166,7 @@ message GameUpdate {
         ShardokActionResultResponse shardok_action_result_response = 4;
         StreamingTextResponse streaming_text_response = 5;
         ErrorResponse error_response = 6;
+        ShardokBattleResetResponse shardok_battle_reset_response = 8;
     }
 
     // Server game status - included with any update type when status changes
@@ -331,6 +332,12 @@ message ShardokActionResultResponse {
     repeated SingleShardokGameResultResponse shardok_game_responses = 1;
 }
 
+// Signal to the client that a tutorial battle has reset (defender lost, battle restarting).
+// The client should clear all Shardok battle state for this game ID and prepare for fresh updates.
+message ShardokBattleResetResponse {
+    string shardok_game_id = 1;
+}
+
 message ErrorResponse {
     SelectedCommand selected_command = 1;
     string error_string = 2;

src/main/scala/net/eagle0/eagle/shardok_interface/ShardokInterfaceGrpcClient.scala

@@ -224,6 +224,8 @@ class ShardokInterfaceGrpcClient(
               )
             )
           // Note: No polling needed - updates are pushed via stream
+          case Specific.BattleResetResponse(_)                 =>
+          // Tutorial battle reset - full handling in follow-up PR
           case Specific.Empty                                  =>
           // Empty response - nothing to process
         }