merge: bring main (v0.1.6) into anim-body-0.2.0

Conflicts resolved by union, not by picking a side:

- AGENTS.md keeps the stronger visual-review rule (README updated with every visual
  change; a stale section is a defect).
- render_screenshots.sh keeps the absolute engine path from main and adds
  -thirdperson from this branch - both were needed and neither alone worked.
- Screenshots/README.md now lists six shots, retail and third-person both embedded;
  the known-issues tables merged, with the animation defect and unproven camera
  collision added to main's rows.
- visual_targets.json carries both expectations.
- Architecture docs: ADR-8 (realistic buildings) and ADR-9 (third-person body) both
  present and in numeric order; ADR-8 was mis-placed before the Quality Requirements
  heading in the combined document by an earlier edit, now fixed.
- Binary conflicts resolved to main's content, since the retail trim only exists
  there.

Checks: 82 tool tests, prettier clean, six embeds resolve.

Tools/ue_build_review_map.py

@@ -300,6 +300,12 @@ try:
             # on the north sidewalk looking along the crosswalk itself, which is
             # the pedestrian's view and shows the zebra bars as bars.
             ("demo-crossing", unreal.Vector(-15250, -2500, 400), unreal.Vector(-14956, 400, 150)),
+            # 0.1.6 retail frontage: 6800 Lee Drug (X -3340..-1417, face Y +1467)
+            # and 6806-6820 (X -6618..-3297, face Y +1252). Stand on the north
+            # sidewalk at 2 m, look south with a level horizon so the parapets and
+            # the cornice line read as horizontals. 68 deg covers both frontages at
+            # this distance; the ends crop rather than the elevation leaning.
+            ("demo-retail-frontage", unreal.Vector(-4700, -2600, 210), unreal.Vector(-4700, 1400, 620), 66.0),
             # the two north-side background buildings (TCL, Tussaud's) seen from
             # the south across Hollywood Blvd. Probed world-space (2026-11-08):
             # TCL bbox X -22889..-18442, Y -9431..-1802; Tussaud's X -27071..