Finishes the steer/transmit loop — advisories now reach the agents' sessions.
- message-sink.js: createEccMessageSink() delivers via the canonical writer
'ecc-tui messages send' (maps steer/hold -> conflict kind, transmit -> query),
resolving the binary from override/env/built target/PATH. Injectable runner;
best-effort (a missing binary/failed send is counted skipped, never blocks).
- proximity.js: createProximityDispatcher() adds per-trigger cooldown so a
persistent collision fires once then stays quiet (agents get steered, not
spammed); runProximityTick() builds the snapshot and dispatches.
- scripts/proximity-tick.js: thin CLI — one-shot, --dry-run, --watch <sec>.
Messages are internal ECC agent-to-agent coordination, not any external channel.
- 14 new tests (sink argv/kind mapping, cooldown dedup, tick dispatch/dry-run,
CLI parse). Full suite 2891/2891; lint green.
Affaan Mustafa