The missing autonomy step: an implementer no longer needs a human prompt
per task. `agenthub work --agent <name> --role <role>` announces, then:
- claims an already-open task addressed to the agent immediately, or
- blocks on the SSE stream until one appears (newly delegated OR
reopened after review), then claims + prints it.
Loop: work → implement → `task review` → work. New/reopened tasks are
picked up automatically; run it in the background so the wait doesn't tie
up the turn.
- src/cli/commands/start.ts: extracted announceAgent / findAddressedOpenTask
/ claimAndPrintTask (shared by start + work); addressed-match now also
covers assignedTo (reopened tasks coming back for rework).
- src/cli/commands/work.ts: wait-and-claim via /events, with a gap-close
re-check after subscribing and an optional --timeout.
- index.ts: `agenthub work` command.
- templates: implementer guides lead with `work` (the autonomous loop),
keep `start` as the one-shot.
- tests: immediate claim (local) + wait-then-claim (server SSE). 119/119.
Bump 0.3.1 -> 0.4.0.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
