Add AutoGen critique crew

- Create CritiqueCrew class with multiple agents:
  - LiteraryCritic (prose quality)
  - GenreExpert (genre conventions)
  - StoryEditor (plot/structure)
  - Writer (revision planning)
- GroupChat for multi-agent discussion
- iterate_chapter() for revision loops
- Factory function create_critique_crew()

opus_orchestrator/__init__.py

@@ -27,6 +27,7 @@ from opus_orchestrator.schemas import (
 )
 from opus_orchestrator.state import OpusState, create_initial_state
 from opus_orchestrator.langgraph_workflow import OpusGraph, run_opus, OpusGraphState
+from opus_orchestrator.autogen_critique import CritiqueCrew, create_critique_crew
 from opus_orchestrator.frameworks import StoryFramework
 
 __all__ = [