Concepts: the editor remembers where each divider was dragged

Concepts names the dividers that are kept and says the sizes belong to the browser, not the project. Architecture names editor/panelSizes.ts. Development counts 1692 editor checks.

Architecture.md

@@ -23,8 +23,11 @@
   header down to the next one (`hiddenBySections`, `sectionOffsets` are the rules, as pure
   functions). A `SortableList` with a title opens a group the same way and draws its band past its
   own edges. The toolkit only folds; which groups are folded is kept by the editor
-  (`editor/sectionFolds.ts`, one entry in `localStorage`). Every title of the inspector goes through
+  (`editor/sectionFolds.ts`, one entry in `localStorage`), and so is where each divider was dragged
-  `addTitle` or `sectionHeader` in `inspector/host.ts`, so a new section gets the band by itself.
+  to (`editor/panelSizes.ts`, a second entry: a name per divider and its width, height or share,
+  read once when the panel is built and held to the bounds the divider keeps). Every title of the
+  inspector goes through `addTitle` or `sectionHeader` in `inspector/host.ts`, so a new section
+  gets the band by itself.
   **Text and boxes sit on device pixels** (`ui/pixelGrid.ts`). The layout counts in whole CSS
   pixels, and on a screen scaled to 125 % or 150 % most of those fall between two device pixels:
   the GPU averages both, text goes soft and a 1 px line becomes a pixel and a half of mixed colour.

Concepts.md

@@ -242,6 +242,13 @@ The asset panel and **Scene objects** share the left column; the divider between
 the height from one to the other, and dragged all the way either keeps its header. The split is a
 share of the column, so a taller or shorter window keeps it.
 
+**Panel sizes are remembered.** Every divider stays where it was dragged, after a reload too: the
+ones left and right of the centre column, the one above the console, the one in the left column,
+the one beside the tilemap panel, the one beside the preview of the Shader, Particles and Pixel
+art tabs (each tab its own), and the one in the user management. The sizes are kept in the
+browser, like the folded groups, not in the project: they hold for every project opened in this
+browser, and another browser starts with the sizes the editor comes with.
+
 **The tab row.** A tab is an **open document**, as in an IDE (#171). **Scene** and **Game** are
 fixed and cannot be closed; a plugin's own tab follows them for as long as the plugin is on. The
 plugins themselves, and for an administrator the accounts, are in a tab that opens from the menu

Development.md

@@ -18,7 +18,7 @@ php tests/php/accounts.test.php                               # the API's accoun
                                                               #   has and the web server's container has not (SKIP there)
 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
-node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1691 editor checks, screenshots in /tmp/gm-e2e-*.png
+node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1692 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