Signal agent health checks instantly

Send synchronous urgent signals between agents with latest-wins overwrite

Gastown health checks and stall detection where only the latest signal matters and fast overwrite is critical

• · NudgeMessage (from, type, message, timestamp, requires_response)
• · recipient agent ID

• · latest.json nudge file

.chipset/state/nudge/{agent-id} directory writable; sender agent ID valid

Nudge lost if reader checks before write completes; requires_response flag ignored if agent offline

• · Single file per agent prevents message accumulation
• · Atomic rename ensures durability
• · Deacon heartbeat pattern integrated