update stale docs, remove unused default personality
- AGENTS.md: remove phi-core ref, Response ref, file tree; add loq-relax
- README.md: fix thought_post_hours default, replace stale architecture
diagram and file tree with pointer to docs/
- docs/architecture.md: rewrite for tool-based actions + scheduling model
- docs/memory.md: add exploration_note kind, review pass, spam handling,
fix [NOW] timestamp format
- docs/testing.md: note eval Response is local, remove sandbox ref
- docs/mcp.md: fix native tools path
- delete personalities/default.md (unused)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>