fix: pass --agent/--add-dir to herdr dispatch; forward --herdr to triage/review

Fixed

• dispatchViaHerdr now passes --agent <spec.agent> and --add-dir <mainRoot> to
  herdr agent start. Without --agent, a herdr-driven session was plain unscoped Claude
  Code, not crew-coder/crew-triage/crew-code-reviewer — the prompt file herdr reads is task
  content only, with no protocol body, and --agent is what tells the session to load
  .claude/agents/<agent>.md and bind its tools: allowlist. Without --add-dir, a coder's
  structured sidecar report (written under mainRoot's .scratch/, outside the worktree cwd
  the session actually runs in) fell outside herdr's directory allowlist — bypassPermissions
  only removes the tool-confirmation prompt, it does not widen scope.
• crew-afk's triage and review dispatches now honor --herdr. runTriage and runReview
  in pipeline.mjs were not forwarding options.herdr down to dispatch(), so with --herdr
  set only the coder actually ran through herdr while triage and review silently fell back to
  the headless claude -p path.