39b7bd31

By: Ammar Nanjiani <ammar.nanjiani@gmail.com>

feat(pi): route GPT-6 Sol and Grok 4.7

Make GPT-6 Sol the Pi default coordinator and review lane. Add Grok 4.7
as the investigative worker. Allow GPT-6 Luna for later trials without
making it a default scout or worker.

Pin Aragorn Hermes to grok-4.7 with gpt-6-sol as the Codex fallback.
Keep gpt-5.6-sol and grok-4.6 in the Pi allowlist during rollout.