phase1 already emits REFLECT: yes|no, but with phase2 off the flag was a
dead-end. Enabling phase2 runs a Critic/Pragmatist/Detailer review pass
before phase3 whenever phase1 flags the task as complex (REFLECT: yes),
feeding "Plan Adjustments" into the execution plan. Skipped for simple
tasks and subagents (gated on `needs_reflect and not is_subagent`), so
the extra LLM call only lands on complex parent-agent work.

Resolves F8 machinery-gap G.

Co-Authored-By: Claude <noreply@anthropic.com>