Bake library AO and lift environment textures

Phase 4 of the v0.6.0 graphics plan:

- tools/bake_ao.py bakes 256² AO maps for every Blender character/gear/prop
  (Cycles, existing UVs) next to each GLB; Materials.apply_ao() wires the red
  channel into character slots, gear, and props. Compatibility has no SSAO.
- Regenerated brick/concrete/asphalt at 1024² with OpenRouter, derived tangent
  normal maps via tools/make_normal_maps.py, and wired them through
  SurfaceMaterials.textured() without changing UV scales.
- Evaluated Forward+: boots on desktop Vulkan, but the renderer is project-wide
  and Web must stay GL Compatibility; v0.6.0 keeps Compatibility (decision in
  MEMORY/plan). A desktop-only override is deferred.
- Recaptured screenshots; compare 11 good / 0 bad. Fixed marquee text alignment.
- Tests: baked AO maps exist for all 46 assets; prop/character AO material
  checks; headless 222/222, Python 69/69, all smokes pass.
- Version 0.6.0; ADR-0013 accepted; README/architecture/blender-assets/plan and
  TODO/DONE updated.

MEMORY.md

@@ -151,9 +151,11 @@ Session memory for durable decisions, state, and gotchas. Keep concise, remove o
   same colliders/obstacles, and collects library emissives for `set_night_mode()`.
   `LIBRARY_TRIANGLE_BUDGET` = 60k (current ~27,986). Library props are excluded from
   `PROP_PLACEMENTS` only when they need dedicated slots (door/marquee/sedan/handrail/lantern).
-- **v0.6.0 remaining:** AO/ORM baking for the library props, higher-resolution environment
-  textures with normal maps, the Forward+ desktop evaluation, then version 0.6.0 docs/release.
-  Headless suite is 222/222 and Python tooling 68/68 after integration.
+- **v0.6.0 environment pass:** `tools/bake_ao.py` bakes 256² AO maps per library asset
+  (`<name>_ao.png`, red channel) and `Materials.apply_ao()`/`SurfaceMaterials` wire them in;
+  `tools/make_normal_maps.py` derives tangent normals for the 1024² brick/concrete/asphalt
+  textures. Forward+ boots on desktop but is rejected for v0.6.0 (project-wide renderer, Web
+  must stay GL Compatibility). Headless 222/222, Python 69/69.
 - **Prop pipeline (done):** audit enforces 400 tris / 600 verts, ground contact, UV range, no
   degenerate tris, one material. `capture_prop_gallery.gd` writes `10-prop-gallery.png` (3x2 studio
   line-up, back row on a platform) and the `prop_gallery` catalogue entry compares it.