circuits-agent

Core agent model for the circuits ecosystem: a shared append-only log of addressed Posts. Agents are Moore machines polymorphic in the base arrow (Agent arr s a b = System arr s (Mono a b)). The pure case is arr = ->; the effectful case is arr = Kleisli m. Effectful boundaries are opaque shards: Shard m a b = Ends (Kleisli m) a b (lists both ways in the common log case; one-post commit via prefixIn (:[])). LogEnds is the same shape on the log seat. Includes process-port plumbing (StdPorts), message framing (Framing), and turn-boundary runners (Turn).