feat(tiles): the grid survives a reload (per device, ids only)

The grid is stored in localStorage `codeman:tile-grid` as
{ v: 1, open, ids, focused, zoomed, colFr, rowFr }: ids, focus, a zoom the
user chose (an automatic one is worked out again from the window) and the
divider fractions, never content. It is written as it changes (layout, focus,
zoom, divider drags); closing the grid keeps it remembered as open: false for
one-click return, and the last tile leaving forgets it. That stored state is
now the only "remembered" grid, so the Tiles toggle, the picker's preselection
and Ctrl/Cmd+click all bring back the grid this device last had, across
reloads. Never written or read in a solo window.

The restore runs INSIDE handleInit, in place of its single-view
selectSession(restoreId, { auto: true }), so with a stored open grid the main
terminal never loads on that page load (its first select would pull a
whole-history capture only to be parked). The stored ids are sanitized against
the session list (deleted, detached and duplicate ids dropped, anything that
is not a v1 object ignored), and the fractions and zoom go back on. A window
too narrow for the grid keeps the single view and the stored grid waits; a
#session= link on load wins and leaves the grid remembered but closed.

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

src/web/public/app.js

@@ -4667,6 +4667,9 @@ class CodemanApp {
 
     // A `#session=<id>` link wins over restoring the last active tab.
     if (this._urlSessionId && this.sessions.has(this._urlSessionId)) {
+      // And over a tile grid stored open: it stays remembered, closed, rather
+      // than reappearing unexplained on the next reload.
+      if (!tilesOpen) this._closeStoredTileGrid?.();
       this.activeSessionId = null;
       this._selectUrlSession();
       return;
@@ -4702,6 +4705,11 @@ class CodemanApp {
         this._splitPane?.reconnectNow?.();
       } else {
         this.activeSessionId = null;
+        // A tile grid stored open on this device (tile-grid.js) comes back IN
+        // PLACE of the single-view restore below, so the main terminal never
+        // loads (its first select would pull a whole-history capture only to
+        // be parked a moment later).
+        if (this._restoreTileGrid?.()) return;
         // `auto`: the app is restoring a session on load, not a human opening
         // one, so a pending idle alert on that tab stays armed until it is
         // actually tapped (see the userInitiated note in selectSession).