Docs: step 2.6 and the crag

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

HANDOFF.md

@@ -40,7 +40,7 @@ TERMINOLOGY (owner-corrected — use precisely):
   `body_spike` "BODY: …", `collapse_spike` "COLLAPSE: …", `arm_spike` "ARM: overall PASS",
   `sixdof_spike` "6DOF: overall PASS" (run FIRST with `weld_spike` whenever the addon binary changes),
   `truebody_spike` "TRUEBODY: overall PASS" (no physics; plain `--headless`), `menu_spike` "MENU: overall PASS"
-  (in-VR menu input injection, no XR). All nine PASS as of this handoff.
+  (in-VR menu input injection, no XR). `ragdoll_spike` "RAGDOLL: overall PASS" (`-- only=a,b` runs the phases whose names contain a or b), `crag_spike` "CRAG: overall PASS" (layout geometry only). Only run the spikes your change touches — the full set takes a while. All nine PASS as of this handoff.
   **Fresh checkout / new worktree: run `godot-mono --headless --import` FIRST** (it may segfault at
   exit — harmless) — without `.godot/extension_list.cfg` the Box3D extension silently doesn't load,
   Godot falls back to its default physics and weld/grab/arm/6dof spikes report CHECK. Headless asset import: