fix: replace non-existent ForgeEpisodeGenerator import with actual exports

ml/training/__init__.py

@@ -9,8 +9,14 @@ from ml.training.rollout_buffer import RolloutBuffer
 from ml.training.reward import compute_intermediate_reward, compute_terminal_reward, RewardConfig
 from ml.training.decision_exporter import DecisionExporter
 from ml.training.forge_episode_generator import (
-    ForgeEpisodeGenerator,
-    AsyncForgeEpisodeGenerator,
+    ForgeTransition,
+    ForgeEpisode,
+    ForgeEpisodeQueue,
+    forge_producer,
+    ppo_consumer,
+    run_forge_pipeline,
+    parse_forge_jsonl,
+    snapshots_to_episode,
 )
 
 __all__ = [
@@ -23,6 +29,12 @@ __all__ = [
     # Decision export
     "DecisionExporter",
     # Forge episode generation (Phase 3)
-    "ForgeEpisodeGenerator",
-    "AsyncForgeEpisodeGenerator",
+    "ForgeTransition",
+    "ForgeEpisode",
+    "ForgeEpisodeQueue",
+    "forge_producer",
+    "ppo_consumer",
+    "run_forge_pipeline",
+    "parse_forge_jsonl",
+    "snapshots_to_episode",
 ]