v1.6.1

📡 Mesh app overhaul (MVP)

• Contacts split from the chat list (chats show only channels + contacts with history; a new contacts screen lists all adverts).
• HH:MM timestamps + touch scrollback in conversations.
• Status line (noise floor / RX / TX / contacts / clock), contact detail view (hops + last seen).
• Touch scroll strip for lists, error-retry button, DM resend on timeout, and multi-ACK tracking for parallel DMs.