fix: bulletproof command handler + auto-restart + README overhaul
- sendStreamingMessage: replaced broken simulated streaming with reliable
HTML send + stripped plain text fallback (was silently failing)
- Added global unhandledRejection guard (catches async errors that
sequentialize middleware would swallow)
- restart.sh: auto-restart loop on crash (3s delay) instead of bare node
- README: comprehensive update with self-learning memory, curiosity engine,
memory architecture diagram, updated command table, updated comparison
