docs: record the facade review traps and release the section claim

Memory gains the camera-side, centre-origin, read-only-map and screenshot-tracking
traps this pass cost. The asset production claim is released: the hero facade
first pass exists and awaits screenshot approval, so the section is free for the
next owner.

MEMORY.md

@@ -95,3 +95,13 @@ Scope: facts and traps that cost time to establish. Planned work lives in [ROADM
 - **Modifiers on `EnhancedActionKeyMapping` do not survive saving.** Assigning `InputModifierNegate` to the mapping's `modifiers` reads back correctly in memory, even after a `gc.collect()`, but the saved asset reads `mods=[NoneType]`. Keep-alive references, explicit flag setting, and in-place saves all failed to change it. Workaround: bind one action per direction (W and S as separate actions) so no modifier is needed.
 - **A read-only packed `.umap` silently blocks `save_map`.** `EditorLoadingAndSavingUtils.save_map` returned `False` with no error until the file's mode was fixed (`chmod u+w`). Symptom: a rebuilt review map keeps three cameras after a fourth is added.
 - `-run=pythonscript` still swallows `print()`, so write results to a file; `/tmp` is visible to the commandlets even though it is not shared between agent tool calls.
+
+## 2026-11-07 — Hero facade build and review cameras
+
+- **The review floor is the only ground in the scene, and it is small.** Cameras 25 m from the building line look past its edge and see the black horizon band under the facade. Place facade cameras so both the facade and enough floor are in frame, or extend the floor.
+- **The facade's frontage faces Unreal -Y.** The FBX preset maps Blender +Y (north) to Unreal -Y, so the elevation looks at negative Y and a straight-on camera must stand at **Y < -1450 cm**. A camera at positive Y looks at the back wall; cameras inside Y -1443..+250 are inside the building and render flat blue.
+- **The imported mesh is centre-origin in X but not in Y or Z.** Bounds are `x -1302..1302, y -7..1250, z 0..1450` cm, so to put the front plane on the building line the actor goes at `Y = line + 7 cm`, and `X = east edge + half width`.
+- **`save_map` returns False, without an error, when the packed `.umap` is read-only.** The review map silently keeps its old camera list. `chmod u+w` the file before rebuilding; a `umap` that keeps rendering four shots after a sixth was added is this, not a caching problem.
+- **`StaticMaterial` is a struct**: `material.get_editor_property("material_interface")`, no `get_name()` on the wrapper.
+- **Screenshot PNGs must stay out of git.** They were committed once despite the AGENTS rule; `.gitignore` now carries `/Screenshots/` with a `!/Screenshots/README.md` exception.
+