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.

Screenshots/README.md

@@ -96,19 +96,23 @@ Known gaps in this first pass, recorded rather than hidden:
 
 ## 6. Third-person body
 
-![Third-person body: the player pawn seen from behind on the north sidewalk](demo/review-demo-third-person.png)
+![Third-person body: the player pawn standing on the north sidewalk, seen from behind](demo/review-demo-third-person.png)
 
 - **File:** `demo/review-demo-third-person.png`
 - **View:** third-person boom, ~6 m behind the pawn, captured with `-thirdperson` so the pawn starts in the third-person rig
 - **Expected content:** the player's own visible body on the north sidewalk, seen from behind, with the hero façade across the street
 - **Verified:** ☑ 2026-11-09 · **Approved:** ☐ pending
 
-What this shot is evidence for, and what it is not:
+What this shot is evidence for:
 
-- **Implemented and visible:** the pawn carries a visible skeletal body with the warm skin material, and a spring-arm camera with collision testing. The **V** toggle swaps first and third person; the shipped default stays first person and the review passes `-thirdperson`.
-- **Not working:** the figure is in **bind pose, arms out**. The idle clip is bound and `PlayAnimation` is called — the run logs `GigLine: playing body clip Character_AnimHuman_rig_GigLine_Idle` — so the call succeeds and the pose does not apply. Tracked in `TODO.md` under "Verify animation plays correctly on the imported rig" with that evidence.
+- The pawn carries a visible skeletal body with the warm skin material, and a spring-arm camera with collision testing. The **V** toggle swaps first and third person; the shipped default stays first person and the review passes `-thirdperson`.
+- **The idle clip now drives the body.** The arms hang at the sides rather than standing out in a bind A-pose, which is what the first three captures of this shot showed.
+
+What is still not right, and is tracked:
+
+- **The arms hang too far forward and the hands splay outward**, so the pose reads as a person standing awkwardly rather than at rest. The base pose is applied to the rest pose with inverted signs (the FBX axis mapping flips it); the elbow and hand orientation still need work, and that belongs to the `0.2.2` skin/animation tuning pass rather than to this rig.
+- **The walk clip has no shot of its own.** It imports and its curves carry a ±18° arm swing and a 0.45 rad hip swing, but nothing has captured it in motion; a walking shot needs a camera that follows a moving pawn.
 - **Camera collision is implemented but unproven:** the spawn point has open space behind it, so no shot exercises the arm shortening.
-- The skin material needed `used_with_skeletal_mesh=True`; without it Unreal silently substituted the default grey, which is what the first capture of this shot showed.
 
 ---
 
@@ -141,8 +145,9 @@ Every issue is tracked in `TODO.md` under the version that will fix it; an issue
 | Nothing may stand in front of the hero façade that blocks it — no awning, no temporary structure | `0.9.0` → per-building models, hero façade | Open |
 | Retail parapet has no moulded profile, and wall lettering built as a plate does not read at 40 m | `0.9.0` → 6800 Lee Drug and 6806–6820, second pass | Open (moved out of `0.1.6`) |
 | 6822 Budget is a bare blockout volume — no photograph exists to model it from | `0.9.0` → photography gap | Deferred (moved out of `0.1.6`) |
-| Third-person body renders in bind pose: the clip is bound and `PlayAnimation` is called, but the pose does not apply | `0.2.0` → verify animation plays correctly | Open (blocks `0.2.0`) |
+| Third-person idle pose reads awkwardly: arms hang forward and the hands splay, because the base pose is applied with inverted signs to compensate for the FBX axis flip | `0.2.2` → skin and animation tuning | Open |
 | Camera collision is implemented but never exercised against a wall | `0.2.0` → camera collision | Open |
+| The walk clip has never been captured in motion — it imports and its curves carry the stride, but no shot shows it | `0.2.0` → verify animation plays correctly | Open |
 | Between kerb and building line the walkable surface is the terrain mesh, not a modelled pavement | `0.6.0` → model the pavement between kerb and building line | Open |
 
 Accepted by the owner, not a defect: