review: restore character + cubes in ReviewMap, re-render all shots

Root cause of the empty review frames: EditorLevelLibrary.load_level/new_level
are deprecated no-ops in -nullrhi commandlets, so staged actors landed in the
current world and got saved over the wrong map. Switched both map builders to
the LevelEditorSubsystem and reordered the review builder to save ReviewMap
before the DemoMap section (the switch-back to a map that only exists in
memory silently failed, writing demo content over ReviewMap).

Rebuilt both maps, re-rendered every screenshot; user visual check passed.
Screenshots/README.md cube naming corrected (A grounded, B floating), approval
states updated; TODO.md visual-review notes closed. MEMORY.md records the
deprecated-call and save-order traps.

MEMORY.md

@@ -164,3 +164,9 @@ Scope: facts and traps that cost time to establish. Planned work lives in [TODO.
 - **`*.blend` and `*.umap` are LFS-lockable in `.gitattributes`** — Git LFS checks them out read-only (444). `bpy.ops.wm.save_as_mainfile` then fails ("path is not writable") and `EditorLoadingAndSavingUtils.save_map` silently returns False. All Blender builders now chmod u+w before saving and treat a failed save as fatal; the UE map builders chmod the .umap first. A failed save used to leave downstream steps building from stale files — that produced a degenerate-mesh FBX (all-same vertex indices from an index-arithmetic bug) that cost an hour to trace.
 - **FBX SDK refuses to triangulate the crown-twisted crossing quads** ("unable to triangulate mesh ... will be omitted") — emit triangles from the builder, and make sure per-stripe vertex indices advance (`len(verts)` must be captured before the loop, not per-corner).
 - Demo-map coordinate note: UE Y is south-positive; the facade at Y −1450 and the player start at Y −3500 are on opposite sides of the road (Y −1382..+1047) — arrangement is correct; the Sidewalk_North/South mesh names are swapped relative to their physical sides (documented in export_site_fbx.py).
+
+## 2026-11-07 — ReviewMap corruption: deprecated level calls + save-order bug
+
+- **`EditorLevelLibrary.load_level`/`new_level` are deprecated no-ops in `-nullrhi` commandlets** (they return without switching worlds, so staged actors land in whatever world is current and get saved over the wrong map). Use the `LevelEditorSubsystem`: `unreal.get_editor_subsystem(unreal.LevelEditorSubsystem).load_level(path)` actually switches. Symptom was ReviewMap containing Demo actors + `ShotSequencer`.
+- **Map-save ordering bug in `Tools/ue_build_review_map.py`**: the script saved ReviewMap *after* the DemoMap section, but the switch back to ReviewMap fails silently because the map only exists in memory at that point — so the final `save_map` wrote the demo world over ReviewMap. Fix: save ReviewMap first, then stage the demo cameras, and never switch back. Both maps verified by probe (ReviewMap lists Review actors; DemoMap lists Demo actors).
+- Rebuilt ReviewMap after the fixes: character, both cubes (A grounded, B floating at 2 m), pawn, NPC prefab, hero facade all present; user re-approved the shots. README cube naming corrected (README had A/B swapped vs the script).