feat(facades): 0.1.6 retail frontage first pass — Lee Drug and 6806-6820

Models the two retail buildings beside the hero from their own photograph rather
than the generic kit: bronze cornice, mural row, lettering band, stepped Deco
parapet and rounded corner tower on 6800 Lee Drug; burgundy fascia, pilasters,
white-framed windows and banded parapet on 6806-6820. Reference analysis written
before any geometry (Art/blender/retail/ref-analysis.md), every unmeasured
proportion carried into the part report as an assumption.

6822 Budget is deferred, not guessed: no photograph of it exists and the 6.0 x 5.5 m
sliver cannot be read out of the neighbour shot.

Pipeline fixes found on the way:
- render_screenshots.sh called ./Engine/... for the capture step while every
  commandlet used the absolute path; set -e killed the script at 127 *after* the
  maps were rebuilt, so screenshots silently stayed a day old.
- the facade kit applies to every Frontage_*/North_* actor, so it pasted its own
  language over the new modelled facades; it now skips them, and the trim stages as
  RetailTrim_*.
- pure bay arithmetic moved to Tools/_common.py so it is unit-testable without
  Blender (4 new tests, 82 total pass).

Known gaps recorded in Screenshots/README.md, not hidden: the parapet reads as a
blank band, murals and lettering do not resolve at review distance, the tower is a
plain cylinder, and the review camera crops the east end.

Screenshots/README.md

@@ -22,6 +22,7 @@ Each shot has an **expectation** in [`Tools/visual_targets.json`](../Tools/visua
 | 2 | `demo/review-demo-street-level.png` | eye height, north side | Street level: the hero colonnade with the adjacent frontage buildings either side, shopfronts at pavement level | ☑ 2026-11-09 | ☑ 2026-11-09 |
 | 3 | `demo/review-demo-crossing.png` | along the crosswalk | The designated mid-block crossing (s=130 m, UE X −14956): zebra bars on the asphalt, south frontage and colonnade behind | ☑ 2026-11-09 | ☑ 2026-11-09 |
 | 4 | `demo/review-demo-north-buildings.png` | across the Boulevard | The two north-side buildings (TCL Chinese Theatre, Madame Tussaud's) from the south side, full height in frame | ☑ 2026-11-09 | ☑ 2026-11-09 |
+| 5 | `demo/review-demo-retail-frontage.png` | north sidewalk, level horizon | The retail run beside the hero: 6800 Lee Drug's bronze cornice, mural row and parapet next to 6806–6820's burgundy fascia, pilasters and window storey | ☑ 2026-11-09 | ☐ pending |
 
 Approval is per shot, in the table above (owner review of the `0.1.4` set, recorded in [`Docs/reviews/0.1.4-review.md`](../Docs/reviews/0.1.4-review.md)). Add a row when a shot is added; remove the file in the same change when a shot is retired.
 
@@ -49,3 +50,20 @@ Note the comparison is only meaningful when the shot and the reference frame the
 - Banners sit on the column line rather than flush to the wall (they hang on the columns in the photographs, so this is acceptable).
 - Between kerb and building line the walkable surface is the terrain mesh, not a modelled pavement.
 - The El Capitan Theatre has no marquee or blade sign yet — the feature that makes it read as itself.
+
+## 0.1.6 retail frontage — what to look at
+
+Shot 5 is the review shot for this pass. Read it against
+`Art/reference/retail-neighbours/01-lee-drug-and-neighbor.jpg` (Gb321, CC BY-SA 4.0).
+
+Known gaps in this first pass, recorded rather than hidden:
+
+- **The parapet reads as a blank white band.** It is modelled as one 2.18 m wall with four
+  0.10 m reveal strips, and at review distance the strips disappear into the wash.
+- **The mural row and lettering band barely read.** They are shallow plates (0.06–0.08 m) on
+  the same plane as the wall; they need either depth or a decal before they read as the
+  photographs' black-framed panels.
+- **The corner tower is a plain cylinder with two cap rings** — the stepped Deco profile in the
+  photograph is richer than that.
+- **The camera crops the east end** of Lee Drug at 68° from the north sidewalk.
+- **6822 Budget is untouched** and still a bare blockout volume: no photograph of it exists.