- New memory_manager.py with:
- check_and_compact: runs compaction on flagged sessions (extracts LTM via
Claude Haiku, stores as AgentCore Memory event, deletes old events)
- check_window_and_flag: sets DynamoDB flag when session > 100 events
- load_ltm: retrieves LTM extractions and formats as system prompt block
- Wired into main.py:
- Compaction runs before session_manager creation (trims old events)
- LTM block injected into system prompt
- Window check runs after session close
- SESSION_WINDOW_SIZE = 100 (named constant)
- Compaction is idempotent (uses event timestamps as cursor)
- LTM retrieval failure is non-fatal (logs and continues)
