fix(eval): parse batch JSON output instead of JSONL for Forge game results

ml/eval/forge_evaluator.py

@@ -270,7 +270,47 @@ class ForgeEvaluator:
         except (subprocess.TimeoutExpired, FileNotFoundError) as e:
             logger.error("[Eval %s] Forge CLI failed: %s -- falling back to synthetic", self.cfg.run_id, e)
             return self._run_synthetic_eval(service)
-        return self._run_forge_via_subprocess(service)
+        return self._parse_batch_json(service)
+
+      def _parse_batch_json(self, service) -> List[GameRecord]:
+        """Parse the batch JSON output from LabCli Java subprocess."""
+        batch_path = os.path.join(
+            self.cfg.results_dir, f"eval-{self.cfg.run_id}-batch.json"
+        )
+        if not Path(batch_path).exists():
+            logger.warning("[Eval] Batch JSON not found at %s — falling back to synthetic", batch_path)
+            return self._run_synthetic_eval(service)
+        with open(batch_path) as f:
+            batch = json.load(f)
+        games_list = batch.get("games", [])
+        if not games_list:
+            logger.warning("[Eval] No games in batch JSON — falling back to synthetic")
+            return self._run_synthetic_eval(service)
+        records = []
+        for idx, g in enumerate(games_list):
+            won = g.get("winningSeat", -1) == 0
+            turns = g.get("totalTurns", 0)
+            pr = g.get("playerResults", [])
+            lp = pr[0].get("finalLife", 40) if len(pr) > 0 else 40
+            lo = pr[1].get("finalLife", 40) if len(pr) > 1 else 40
+            records.append(GameRecord(
+                game_index=idx,
+                won=won,
+                turns=turns,
+                life_final_policy=lp,
+                life_final_opponent=lo,
+                life_delta=lp - lo,
+                commander_damage_dealt=0,
+                illegal_actions=0,
+                entropy_mean=0.0,
+                inference_ms_mean=0.0,
+                decision_steps=turns,
+            ))
+            if len(records) >= self.cfg.num_games:
+                break
+        logger.info("[Eval %s] Parsed %d games from batch JSON", self.cfg.run_id, len(records))
+        return records
+
     def _run_forge_via_subprocess(self, service) -> List[GameRecord]:
         """Parse JSONL files produced by a separately-launched Forge batch."""
         records = []