Per-host personalization for DSH

Key features

• Custom instructionsa user-written block injected into every session's system prompt.
• Client settings sectionsettings.section (id personalize, order 210)
• Add entries manually, or let the agent collect automatically via tools (memory_create, memory_list, memory_delete)
• Every deletion asks for confirmation first — nothing is removed silently
• Reply-tone presetswarm & friendly / direct & efficient / precise & professional / playful & humorous / custom — injected as a prompt section.