swarm: the contract for an agent's bash task status and output

A status key per task in the bash-task-status bucket and the task's output rows
in a per-agent stream, kept apart as for subagents. The controller creates the
bucket and the streams, and the agent credential may publish its own keys and
subjects. Nothing publishes yet; the bash MCP half follows.

swarm-controller/Cargo.toml

@@ -117,6 +117,7 @@ swarm-queue-client = { workspace = true, features = [
   "kv",
   "agent-permissions",
   "subagent-term",
+  "bash-task",
   "agent-term",
   "forge-events",
 ] }