Record the Godot import-cache gotcha and ashlar decision

MEMORY.md

@@ -4,6 +4,21 @@ Session memory for durable decisions, state, and gotchas. Keep concise, remove o
 
 ## Decisions
 
+- **Godot 4.7.2 `--import` gotcha (2026-11-03):** with a stale `.godot/` cache, `--import`
+  (and `--editor --quit-after N`) scans new image files but never imports them — no `.import`
+  files are created, and `preload()` of the new texture then fails to compile every dependent
+  script (the confusing `Could not resolve external class member "spec"` comes from
+  `game_manager.gd`, not the texture). A brand-new file still not importing after several runs
+  is the signature. Workaround that works: run the import in a scratch copy with `.godot/`
+  removed (`rsync -a --exclude .godot --exclude tmp --exclude .git ./ /tmp/proj-copy/` then
+  `godot --headless --import` there), and copy back the generated `.png.import` plus the
+  matching `.godot/imported/*.ctex/.md5`. CI is unaffected (it imports fresh and `.import`
+  files are committed).
+- **Ashlar limestone pick (2026-11-03):** the masonic facade field uses
+  `limestone_ashlar[_normal].png`, generated reference-anchored on the 2009 CC BY facade photo,
+  768 px tile ≈ 4.6 m of wall (~167 px/m, inside the 40–400 band). `stone_steps` stays for trim;
+  facade tint warm-shifted to `Color(0.85, 0.81, 0.74)`. Night emissive balance and
+  banner/canopy materials are still open in the facade-realism item.
 - **OpenRouter reference-anchored generation (2026-11-03):** the `/v1/images` endpoint takes no
   input image; the working image-to-image path is `POST /v1/chat/completions` with a
   `content` array (`{"type": "image_url", "image_url": {"url": "data:...;base64,..."}}`).