v5.1.1: Logging UX & Stability Patch

Highlights\n- Visual Logging: Better distinction between Brain, Hassan, and Orchestrator actions.\n- Completion Logic Fix: Prevents redundant Hassan calls after task completion.\n- Graceful Shutdown: Automatically flushes and saves logs even if interrupted by Ctrl+C.\n- Infinite Loop Prevention: Limits Self-Check retries to 2 attempts.