fix(screenshots): level the elevation cameras for straight verticals

archviz rule: an elevation must not lean. hero-facade-front looked up ~4 deg from
4.2 m at a 7.6 m target (columns converged); demo-spawn-view and demo-street-level
were pitched too. All three now sit at the target's height, so pitch and roll are
zero by construction and the verticals stay parallel.

Screenshots re-rendered. A pixel-based verticality check is useless here (banners
and windows break naive edge matching), so the guarantee is geometric and is
recorded that way in the README and MEMORY.

MEMORY.md

@@ -495,3 +495,15 @@ Scope: facts and traps that cost time to establish. Planned work lives in [TODO.
   `v0.1.2` cut after the merge.
 - Assumptions recorded rather than hidden: dentil spacing, base and abacus
   dimensions are not resolvable in our reference photography.
+
+## 2026-11-09 — elevation cameras levelled (straight verticals)
+
+- archviz MUST: an elevation must not lean. `hero-facade-front` looked up ~4° from
+  4.2 m at a 7.6 m target; `demo-spawn-view` and `demo-street-level` were pitched
+  too. All three now put the camera at the target's height, so
+  `FindLookAtRotation` yields pitch 0 and roll 0 and verticals are parallel by
+  construction.
+- Do not try to *measure* verticality from the rendered PNG with a naive edge
+  scan: banners, windows and the parapet produce different edge sets at different
+  heights and the pairwise match is meaningless (it reported a 418 px "drift").
+  Verify it geometrically in the camera list instead.

Tools/ue_build_review_map.py

@@ -236,7 +236,11 @@ try:
         # the plinth, which is what "portal detail" means here.
         ("hero-portals", unreal.Vector(hero_x + 100, -2250, 170), unreal.Vector(hero_x + 100, hero_y, 230)),
         # straight on from the north sidewalk; the building body spans Y -1443..+250
-        ("hero-facade-front", unreal.Vector(hero_x + 200, -3200, 420), unreal.Vector(hero_x, hero_y + 400, 760)),
+        # Level horizon: camera height == target height, so the elevation's
+        # verticals stay parallel. The old shot looked up ~4 deg from 4.2 m at a
+        # 7.6 m target, which converged the columns — the one thing an
+        # architectural elevation must not do (archviz: "straight verticals").
+        ("hero-facade-front", unreal.Vector(hero_x + 200, -3200, 760), unreal.Vector(hero_x, hero_y + 400, 760)),
         # oblique from the north-west, reading the colonnade in depth
         ("hero-facade-oblique", unreal.Vector(hero_x - 2200, -3400, 620), unreal.Vector(hero_x + 300, hero_y, 700)),
     ]
@@ -276,12 +280,14 @@ try:
         demo_shots = [
             # 14 m back so the 14.5 m elevation fits: at 2 m the camera sees only
             # the colonnade's underside.
-            ("demo-spawn-view", unreal.Vector(-13336, -3100, 420), unreal.Vector(-13336, 1300, 620)),
+            # Level horizon for the same reason: a block elevation is read by its
+            # verticals, and a pitched camera makes them lean.
+            ("demo-spawn-view", unreal.Vector(-13336, -3100, 620), unreal.Vector(-13336, 1300, 620)),
             # Street level, from the north sidewalk: the old camera sat at Y -400,
             # inside the facade body (which spans Y -1457..-200), so it looked at
             # the unlit back face. Y -2600 is on the sidewalk in front of the lit
             # elevation.
-            ("demo-street-level", unreal.Vector(-13420, -1650, 170), unreal.Vector(-13336, 1300, 400)),
+            ("demo-street-level", unreal.Vector(-13420, -1650, 170), unreal.Vector(-13336, 1300, 170)),
             # The designated mid-block crossing. Street arc length runs from the
             # west end (s=0 at X -27966 cm), so s=130.1 m is UE X -14956, not the
             # -24291 the old camera used (that is the s=36.6 crossing). Camera sits