feat(worker): extend RunResult with structured output, session ID, and token metrics

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Worker/Runner/RunResult.cs

@@ -5,6 +5,11 @@ public sealed class RunResult
     public required int ExitCode { get; init; }
     public string? ResultMarkdown { get; init; }
     public string? ErrorMarkdown { get; init; }
+    public string? StructuredOutputJson { get; init; }
+    public string? SessionId { get; init; }
+    public int TurnCount { get; init; }
+    public int TokensIn { get; init; }
+    public int TokensOut { get; init; }
 
     public bool IsSuccess => ExitCode == 0 && ResultMarkdown is not null;
 }