Describe name plates and label rows in the scene view

Development: e2e sum 1382 (computed).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Development.md

@@ -14,7 +14,7 @@ npm run build        # writes dist/ and regenerates index.html
 ./build.sh           # the same under `set -o pipefail`, for callers that pipe the output
 php tools/make-user.php <name> <password> [admin|user]        # an account; every tool signs in (see Accounts)
 php tests/php/accounts.test.php                               # the API's account rules, no server needed (CI's gate job)
-node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1381 editor checks, screenshots in /tmp/gm-e2e-*.png
+node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1382 editor checks, screenshots in /tmp/gm-e2e-*.png
 GM_STEPS=20 node tools/e2e.mjs                                # or 1-12, or 6,20 — a subset while working on one step
 ./e2e.sh start [GM_STEPS]                                     # the same run detached, see below
 ./e2e.sh status                                               # live progress, or the last run's result

Scene-editing.md

@@ -52,6 +52,13 @@ icon is clicked like its object: a click selects it and a drag moves it, even wh
 over a sprite, and the selection outline of a behavior, container or rigidbody is drawn round its
 icon. Beside the icons the sprite underneath is picked as before.
 
+**Names stand on plates, in rows of their own.** A symbol's name is drawn in the light label colour
+on a dark, 70 % opaque plate, so it reads on any ground, and a selected object's plate gets an
+accent frame. A name that would cover another name or an icon moves a row down, up, two down and so
+on until the row is free (`stackLabels`, `src/viewport/labelRows.ts`). Names are placed top to
+bottom, so the upper of two keeps its row, and a name only moves up or down: it stays on its icon's
+side. Names off screen take their row as well, so none jumps while the view pans.
+
 **Z-order is part of the position.** `position.z` is the draw order of a scene object: higher
 `z` is drawn on top; objects with equal `z` keep their hierarchy (tree) order. It is edited in the
 inspector next to X/Y, undoable like any move, and applies in edit and play mode alike. The layers