fix(anim): the clip now drives the body — two causes, both measured

The body stood in an A-pose while the log said the clip was playing. Two
independent defects, found by querying the imported asset instead of guessing:

1. PlayAnimation needs the component in AnimationSingleNode with a live
   single-node instance. The body is hidden at construction and only unhidden by
   the camera toggle, so the first call could land before the component was ready,
   and the Wanted == PlayingAnimation guard then returned forever. UpdateBodyAnimation
   now sets the mode, calls SetAnimation + Play, and re-asserts while the instance
   is missing.
2. The arms-down offsets lived only in the clip keys. The exporter writes clip data
   relative to the rest pose, so they arrived as a ±20 degree swing around an
   A-posed bind - which is exactly what the pose probe measured. apply_base_pose now
   bakes them into the rest pose before any clip is authored, the same trick
   mpfb_character_export.py --pose idle uses. The table is applied with inverted
   signs: as written, the FBX axis mapping produced arms raised in a V.

Shot 6 confirms it: the arms hang at the sides. Still open and recorded - the idle
pose reads awkwardly (arms forward, hands splayed) and the walk clip has no shot in
motion; both are marked in TODO.md and Screenshots/README.md.

Instrumentation removed; the diagnostics that remain are behind
gigline.SetupLogs.

MEMORY.md

@@ -474,3 +474,7 @@ Scope: facts and traps that cost time to establish. Planned work lives in [TODO.
 - **The material was a real but separate defect**: `M_Character_Export` had no `SkeletalMesh` usage flag, so Unreal substituted the default grey with only a `LogMaterial` warning. Fixed in place (`used_with_skeletal_mesh = True`).
 - **`PlayAnimation` alone is not enough.** `USkeletalMeshComponent::PlayAnimation` needs the component already in `AnimationSingleNode` mode; the body is hidden at construction (`SetHiddenInGame(true)`) and only unhidden by the camera toggle, so the first call can land on a component that is not yet in the right mode and never retries — the guard `Wanted == PlayingAnimation` then returns forever and the pose stays at bind.
 - **What to log next time**: animation mode and `GetSingleNodeInstance()` together with the clip name. A clip name alone shows the intent, not the effect.
+- **Fixed 2026-11-09, two independent causes.** (1) `PlayAnimation` needs `AnimationSingleNode` plus a live single-node instance; the body is hidden at construction and only unhidden by the camera toggle, so the first call could land before the component was ready and the `Wanted == PlayingAnimation` guard then returned forever. `UpdateBodyAnimation` now sets the mode, calls `SetAnimation` + `Play`, and re-asserts while `GetSingleNodeInstance()` is null. (2) The arms-down offsets lived only in the clip keys — the exporter writes clip data **relative to the rest pose**, so they arrived in Unreal as a ±20° swing around an A-posed bind. `apply_base_pose` now bakes them into the rest pose before any clip is authored, which is what `mpfb_character_export.py --pose idle` already did.
+- **The base pose needs inverted signs when baked to rest.** Applied as written, the FBX axis mapping produced arms raised in a V; negating the table gives arms down. Both states were verified on the imported asset, not assumed.
+- **Unreal bone names use underscores**: `upperarm01_L`, not Blender's `upperarm01.L`. `GetBoneIndex(TEXT("upperarm01.L"))` returns INDEX_NONE, `GetBoneTransform` then returns identity, and a probe reading it reports a constant 0.0000 — which looks like "animation not applied" and is actually "bone not found". Check `AnimPose.get_bone_names()` before trusting any bone probe.
+- **`Log` verbosity does not reach the capture log, `Warning` does.** Two diagnostic runs produced zero lines because the messages were `UE_LOG(LogTemp, Log, ...)`; the same lines at `Warning` appeared. Instrument with Warning when the evidence has to survive into `/tmp/gigline/render-*.log`.