Roadmap Tier 3 — moved

Consolidated into docs/PLAN.md.

Roadmap Tier 3

Absorbed into the master plan. Most Tier-3 items shipped; RLHF/PPO is in §2 (skipped — DPO covers 80-90% of the lift), Constitutional AI in §2 (blocked on local judge), ReLoRA in §3 (unshipped technique residue).