Document Tree of Art layouts, colour helpers, deep-links, and caption i18n.

Co-authored-by: Cursor <cursoragent@cursor.com>

Documentation/movement-tree.md

@@ -81,6 +81,15 @@ change.
 Clicking any limb or label opens the movement's artist picker and then its 3D movement
 gallery, exactly as the other two layouts do.
 
+## Colours and captions
+
+- Limb fill/shading uses [`utils/movementColor.ts`](../client/src/utils/movementColor.ts)
+  (`vividMovementColor`, `shadeMovementColor`) — the same helpers as the classic and
+  vertical charts. Malformed catalogue hex falls back to the input string; values longer
+  than six digits keep the first six (`#rrggbbaa` → `#rrggbb`).
+- The chart hint under the canvas is `captionTreeFlow` in
+  `locales/{en,ru}/home.json` (same pattern as the other layouts).
+
 ## Tuning
 
 All constants sit at the top of the two files and are safe to tune: