touch abstract method

Future<void> touch(
  1. String agentId, {
  2. bool busy = false,
})

Refreshes agentId's liveness marker (a heartbeat): hosts call this periodically while the agent runs so directory consumers can tell live mailboxes from abandoned ones WITHOUT any pending mail. busy reports an agent run in progress (mail still accepted — steering semantics); a fresh busy beats the liveness heuristics in directory views. Best-effort by contract — a failing backend never breaks the caller's loop.

Implementation

Future<void> touch(String agentId, {bool busy = false});