Docs: session log Part R + roadmap tick — Phase 1.5b bundle 4 shipped, 1.5b COMPLETE

Bundle 4 (critters + weather beats) shipped; all four World-Alive-II bundles
done. Next = the operator's Phase 1.5 gate lap.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Docs/Vault/06_Roadmap/Iteration_2026-07_CoopHades.md

@@ -183,9 +183,14 @@ plain"** — expand 1.5 before 1.7. Locked bundles, sequenced ground-first:
    (absolute-tick disc + latched/armed crossing burst — NEVER edge-detect the field; reuses bundle-2 scorch).
    Seeded in `RoomFieldSystem` (born-correct staggered), spawner wired into the subscene. 474/474 + live
    no-storm end-to-end. See [[Geyser_Build_Spec]].
-4. **Critters + weather beats**: fleeing bugs/birds; cloud-shadow drifts; Blight lightning flicker.
+4. ✅ **Critters + weather beats** (SHIPPED, Part R): client-only `AmbientLifeSystem` (+ `AmbientLifeConfig`) —
+   fleeing bug/bird pool (dart out of the flee radius = the scatter beat, biome-tinted), drifting cloud-shadow
+   discs, and Blight-room-only double-blink lightning flash + thunder (dedicated flash light, no RenderSettings
+   conflict). Reuses the `FeedbackFx` disc/scorch primitives; 474/474 + live-verified at base.
 
-Gate: the same "no longer static" lap, now with the ground judged explicitly.
+**Phase 1.5b COMPLETE (all four bundles shipped).** Gate: the "no longer static" lap, now with ground + decals
++ geyser + critters/weather judged explicitly (the biome-gated beats — geyser erupt, Blight lightning — seen in
+a real Blight room).
 
 **Gate:** operator playtest says "no longer static"; node harvest feedback visibly works; art direction LOCKED.