docs(pipeline): register Track MP in roadmap + milestones freeze exception

Roadmap gains the Track MP phase table (MP0 in progress, MP1-MP5 ahead);
milestones doc records the side track + the explicit user-authorized
freeze exception (MP may reopen frozen streaming/WB-rendering subsystems
under its own gated phases only); CLAUDE.md Current state gets the
one-line pointer.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/plans/2026-04-11-roadmap.md

@@ -1180,6 +1180,27 @@ port in any phase — no separate listing here.
 
 ---
 
+### Track MP — Modern Pipeline (performance side track; user-commissioned 2026-07-05)
+
+**Spec:** `docs/superpowers/specs/2026-07-05-modern-pipeline-design.md` (the
+umbrella design — read it first). **Goal:** smoothness first (no frame over
+~16 ms during any traversal), then 300+ FPS sustained in dense towns.
+Perf-only per `feedback_render_perf_not_faithfulness_gated` — pixels and
+game-feel stay identical; the simulation's retail-mirroring OO structure is
+untouched. NOT part of M1.5 — runs in dedicated side-track sessions; M1.5
+critical path wins every conflict.
+
+| Phase | What | Status |
+|---|---|---|
+| MP0 | Honest frame profiler (`[frame-prof]`) + baseline capture | 🔵 IN PROGRESS — code shipped 2026-07-05 (plan `docs/superpowers/plans/2026-07-05-mp0-frame-profiler.md`); baseline capture pending |
+| MP1 | Baked asset pak (`acdream-bake` CLI + mmap zero-copy `PakReader`) | ⚪ next after the MP0 gate |
+| MP2 | Retail distance-degrade port, hide-only cut (retires a divergence row) | ⚪ |
+| MP3 | Arch ECS render world + delta submission (the 300-FPS lever) | ⚪ |
+| MP4 | Zero-alloc frame loop + flat physics data | ⚪ hard-queued behind M1.5 #137 |
+| MP5 | Job-system parallelism | ⚪ stretch, evidence-gated |
+
+---
+
 ## Cross-cutting work tracked in parallel
 
 - **Test coverage.** Each phase lands with unit + integration tests in `tests/`. Current count: 98 Core + 96 Core.Net = 194. Keep the ratio as new phases land.