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/visual_targets.json

@@ -49,6 +49,18 @@
       ],
       "expect": "The two north-side buildings (TCL Chinese Theatre, Madame Tussaud's) seen from across Hollywood Boulevard, full height in frame, daylight"
     },
+    {
+      "name": "demo-retail-frontage",
+      "shot": "Screenshots/demo/review-demo-retail-frontage.png",
+      "size": [
+        1920,
+        1080
+      ],
+      "references": [
+        "Art/reference/retail-neighbours/01-lee-drug-and-neighbor.jpg"
+      ],
+      "expect": "The retail run beside the hero from across the street: 6800 Lee Drug's bronze cornice, mural row and stepped parapet next to 6806-6820's pilasters and window storey, daylight"
+    },
     {
       "name": "demo-third-person",
       "shot": "Screenshots/demo/review-demo-third-person.png",
@@ -62,4 +74,4 @@
       "expect": "Third-person view of the player body standing on the north sidewalk, full figure visible from behind, the hero facade across the street, daylight"
     }
   ]
-}
+}