Render-clock tracking timestamps (menu toggle), physics step cap 6, docs for step 2.7

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

AGENTS.md

@@ -321,7 +321,7 @@ device only; the editor has an XR simulator for dev. Trackers/action map: see `x
    `PhysicsMaterialOverride` before AddChild.**
    **Step 2.6:** landing DIP is physics (legs touch down only within reach → leg strength stops the body below
    its stance; big falls fold the legs, Boneworks-style; rise eased so gravity alone can stop it at the stance);
-   JUMP on right A (countermovement dip + leg push over the stroke — crouching first jumps higher); STICK CROUCH on
+   JUMP on right A (2.7: hold to charge, release to jump; crouching charges too); STICK CROUCH on
    right stick Y (`RagdollDriver.StickCrouch` = virtual floor offset); body facing from `BodyMath.HeadFacing`
    (no flip looking down past vertical); the XR origin is DRAWN interpolated like the bodies (`PlayerRig`
    `_physOrigin`, restored before physics) — the camera/body "two places at once" desync. Rule learned: play-space
@@ -330,6 +330,13 @@ device only; the editor has an XR simulator for dev. Trackers/action map: see `x
    **The crag** (`Crag.cs`): a 26 m box-rock cliff north of the playground with one graded route (boulders →
    ladder → 8 m ledge → jug wall → traverse → overhang → 16 m ledge → chimney → summit with props); the way down
    is the "Crag" teleport marker at the base. Regression `scenes/crag_spike.tscn` "CRAG: overall PASS" (layout only).
+   **Step 2.7 (owner 2026-10-02: "Nimso's project is the main source of inspiration/mechanics — don't reinvent
+   the wheel"; check `research/nimso-project-tx.md` + `research/sources/nimso-transcripts/` FIRST for any body
+   mechanic):** ground under the BODY (centre ray + stance-wide sphere footprint), clambering by PRESSURE (higher
+   ground is stood on once the hips are over it and the body presses onto it — no special mantle mechanic),
+   capsule hips (Nimso ~27 cm), heavy physics objects brace like world, arms always collide with held things,
+   SOFT GRAB (`SoftGrab.cs`: eased into the hand before the weld), hold-A-to-charge jump, render-clock-timed
+   tracking (`PoseFilter` sampleTime; menu toggle "Tracking: steady/low lag"), physics step cap 6.
    Owner scope: avatar scaling and NPCs later.
 10. **Body physics Stage 2 — PHYSICAL ARMS, implemented 2026-10-02, awaiting owner playtest.**
    `PhysicsArms.cs`: per side an upper-arm + forearm RigidBody3D (2.0 / 1.2 kg, layer 5) that