v0.6.6

DevSpec can now tell you an agent has stopped listening

• "Live" used to mean "the process is up", which is not the same as "work sent here will be read." 0.6.5 stopped an agent going deaf in the first place; this reports the state honestly if it ever happens anyway. The poller now checks whether a wake listener actually holds the pidfile, counts any owner commands sitting unconsumed in the inbox, and sends both on the heartbeat it already makes. DevSpec shows such an agent as Not reading rather than Live, and stops offering it as available to dispatch to.
• Armed is proved by a live pid, never by a leftover file — a hard-killed listener leaves its pidfile behind, and trusting that would report exactly the lie this is meant to catch.
• It will not cry wolf. A missing pidfile only counts as evidence once this connection has armed a pidfile-writing wait at least once. Waits armed before that shipped never wrote one, so "no file" from them means "older build", not "deaf" — otherwise every healthy pre-upgrade agent would light up as Not reading at the very moment you were deciding whether to trust the new badge.

Items 8b4ceaa3, d655b2a4.