Agentcomm

Fixes the daemon warm-up stampede on large buses (#144, #145):

• The daemon binds its socket before warming its mirror — clients connect immediately instead of spawning duplicate daemons for the entire warm-up window.
• Git-backed buses warm in one round trip (new Snapshottable backend capability: one fetch + ls-tree + cat-file --batch) instead of one network fetch per key.
• Backends without snapshot support no longer prefetch bodies during polls — the github:// warm drops from ~1 REST call per key to a single list call.
• Clients only remove a daemon's socket when its process is actually dead, so a transient connect error can no longer orphan a live daemon.
• GitBackend fetches are serialized per instance and retried on ref-lock collisions — previously a collision between the poll, the outbox flusher, and a client op made inbox silently return empty.

Upgrade: npm install -g @yonidavidson/agentcomm@latest