docs(tiles): a reload brings the grid back only when it was open

The wiki, decision 11 in the tile-grid plan, its Persistence section, the
layout-memory test header and two tile-grid.js comments said the Tiles
button and a page reload bring the grid back however it was closed. Only
the Tiles button does: a grid closed before the reload stays stored as
open: false, the page shows the single view, and the toggle puts the grid
back. The behaviour was right; the wording now says that.

A test pins it through the real close path: arrange the grid, close it with
the toggle, start a fresh page, and the restore leaves the single view
while the toggle still brings back the cells, count, divider sizes, focus
and zoom. ('a stored closed grid leaves the single view' in
tile-grid-restore.test.ts covers the same from a raw stored value through
handleInit.)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/wiki/Tile-Grid.md

@@ -98,8 +98,8 @@ keeps the focus.
 
 A moved tile takes the size of the place it lands in: column widths and row heights stay
 where you dragged the dividers. Tiles do not move while one is zoomed. Where everything is,
-the empty slot included, is saved with the grid and comes back on reload and when you turn
-the grid off and on.
+the empty slot included, is saved with the grid and comes back when you turn the grid off
+and on, and on a page reload while the grid is open.
 
 Closing a tile leaves its place empty when the grid keeps its shape (six tiles to five), and a
 new tile takes the first empty place. When the number of tiles changes the grid's shape (four
@@ -135,7 +135,9 @@ same. Narrowing the window below the desktop width also returns to the single vi
 The grid is saved in this browser every time you change it (moving, resizing, adding or
 removing a tile, changing the count, focusing or zooming a tile), and never sent to the
 server. However you leave it (the Tiles button, another tab, Home, a link, closing its last
-tile or session), the Tiles button and a page reload bring it back as it was. A session
+tile or session), the Tiles button brings it back as it was. A page reload brings it back
+when the grid was open; after you left it, a reload shows the single view and the Tiles
+button still brings the grid back. A session
 that was closed in the meantime frees its place for another one, picked the way a new grid
 picks them; the place stays empty only when no other session is left. Right after a page
 reload the page does not know yet which sessions are waiting for your answer, so that pick