fix(i18n): zh-CN for the Redraw toasts, and comments that named old defaults

Redraw (Ctrl+Shift+R and the header button) shows five literal toasts and a
size report on the main pane, a tile or the split's Pane B. None had a zh-CN
entry, including the two the final checkup's tile Redraw fix added, and
"Failed to restore terminal size" fell to the generic "Failed to" pattern,
which left English behind. They now translate, and the size report keeps its
numbers through a pattern rule. test/redraw-toast-i18n.test.ts reads the
toasts from restoreTerminalSize() itself, so a reworded one without an entry
fails.

Comments and docs that still described an older default:
- styles.css: the Tiles header button is no longer opt-in; it is on by default
  on desktop and off on phones and coarse-pointer tablets.
- terminal-ui.js: the desktop branch of getDefaultSettings is no longer always
  {}; what the comment needs is that it sets no copyStripMargin.
- docs/tile-grid-plan.md: the Tiles default bullet names the tablet default.
- docs/cli-registry.md: codex's footer is read in a two-row window since
  codex 0.162's hint row, not from its last row.

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

docs/tile-grid-plan.md

@@ -21,8 +21,9 @@ or settled a question the spec left open. The invariants as built are in
   the setting off the toggle chord is inert. A grid opened another
   way (Ctrl/Cmd+click, a dropped tab, "Open group as tiles") keeps all its chords.
 - **The Tiles button ships ON** (owner, 1.36.0 beta): `showTileGridButton` defaults to on
-  everywhere but handhelds (their defaults object keeps it off), so the chord is live by
-  default too. An absent key resolves through the device defaults in both the button
+  everywhere but handhelds (their defaults object keeps it off) and, since the 1.40.0 final
+  checkup, devices whose primary pointer is coarse (touch tablets, opt-in there), so the
+  chord is live by default too. An absent key resolves through the device defaults in both the button
   (settings-ui.js) and the chord (`tileShortcutFor`), so they cannot disagree.
 - **Dividers are grid tracks.** Each gap between columns and rows is its own 6px track (the
   grid gap is 0) and every tile and every empty slot is placed explicitly in its cell