Describe the zoom transition of the music tabs and the EQ (#377)

The Pattern, Song and Sound tabs and the Parametric EQ now show their
zoom as a transition too.

- Concepts names the music tabs and the EQ under the zoom transition.
- Architecture names axisTween in viewTween.ts.
- Development counts 1941 e2e checks.

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

Architecture.md

@@ -285,7 +285,8 @@ src/editor/            App → Editor (layout + ticker), PlaySession (the run),
                        the screen, one entry in `localStorage`), viewTween (#309: a wheel step or Fit as a
                        transition; `tweenView` is the way between two views as a pure function, `ViewTween`
                        drives it on the ticker, and each zoomable surface hands it reading, writing and
-                       drawing its own view),
+                       drawing its own view; `axisTween` is one for a single axis, as the music tabs,
+                       whose axes zoom apart, keep one per axis, #377),
                        EditorRun (run in editor), state, actions (what several places do alike: `removeSelection`
                        is Delete for every kind of selection, one case each, `removeShapes` the shapes of a vector
                        art), shortcuts, clipboard (#240: copy and paste of

Concepts.md

@@ -347,7 +347,10 @@ one kind can be open at once — two textures, three behaviors — each with its
   both are where you left them.
 - A wheel step and **Fit** are shown as a short **zoom transition** (#309) wherever the editor
   zooms: the Scene and Container tabs, the Texture, Curve, Pixel art and Vector art tabs, the
-  Animation tab's preview and timeline, the graph, the Tile tab's board and a plugin's node board.
+  Animation tab's preview and timeline, the graph, the Tile tab's board and a plugin's node board,
+  and in the music tabs (#377) the Pattern, Song and Sound tabs and a Parametric EQ's curve. There
+  the time across and the rows, tracks or height down zoom apart, and each goes its own way; the
+  EQ's dB lines slide to their new place already labelled with the range it is heading for.
   How long it takes is set in *Menu → General settings…* in milliseconds, 200 by default; 0 jumps
   at once. The steps are the same as without it: quick wheel steps add up to exactly as many
   steps, and the point under the pointer stays under it all the way. A pan, another document or a

Development.md

@@ -19,7 +19,7 @@ php tests/php/accounts.test.php                               # the API's accoun
 php tests/php/snapshots.test.php                              # the snapshot store (#231), the same way
 php tests/php/releases.test.php                               # the release store (#266), the same way
 php tests/php/files.test.php                                  # uploaded files in a folder per account (#344), the same way
-node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1937 editor checks, screenshots in /tmp/gm-e2e-*.png
+node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1941 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