feat(facades): 0.1.6 retail second pass — relief, material mapping, framing

What the first pass got wrong, and what changed:

- The mural plates were placed 0.20 m INSIDE the solid blockout volume, so they
  never rendered. Nothing can be recessed into a solid we do not cut: the inset is
  now faked by a proud frame with a near-flush plate, and the row reads.
- Detail sat 0.05 m off the wall, under a pixel of depth at 40 m. Trim planes now
  stand 0.10-0.20 m proud, and the parapet became two tiers with deeper reveals.
- 6806's parapet started at 0.62 H and left a 4.6 m blank band; the window storey
  and parapet moved up to follow the photograph.
- Security bars on the upper windows, twelve fluted fins on the corner tower.
- The trim's stucco/white/glass slots are mapped onto the demo's look materials, so
  the walls sit in the same noise/texture family as the rest of the block; the
  colour slots sampled from the photograph stay as authored.
- Review camera pulled back and widened to 66 deg so the east end is in frame.
- The scene audit caught duplicate RetailTrim_ actors: the demo builder's clear list
  did not include the new label, so every rebuild stacked another copy.

Still open and not fixable by geometry: wall lettering. A plate at 0.10 m does not
read at 40 m, so it moves to the 0.9.0 decal route (TODO.md, Screenshots/README.md).

Screenshots/README.md

@@ -85,8 +85,8 @@ Read this one against the reference photograph it was modelled from: `Art/refere
 
 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 parapet still reads as a blank band.** It is now two tiers with three deeper reveals, and the step is visible, but there is no profile or shadow line to break the wall — a moulded coping and a modelled reveal need the `0.9.0` façade system.
+- **The mural row now reads** (framed plates standing 0.12–0.20 m off the wall), but **the lettering band does not**: it is a plate at 0.10 m and it disappears at 40 m. Wall lettering is a decal/texture problem, scoped in `0.9.0`; no amount of extra plate depth fixed it in the second pass.
 - **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.