refactor: the kept versions are offered at a failed load, not in the menu

A list of timestamps in both file menus paid for itself only on the day
something went wrong, and it was in the way on every other. The entries
are gone; loadDocument now offers the versions where the browser copy has
actually failed the reader — newest first, one question each, and the one
taken up starts under the boot flag like any other document. The store
loses its reactive singleton with them.

src/App.svelte

@@ -46,7 +46,6 @@
   import { loadLineNumbering, saveLineNumbering, DEFAULT_LINE_NUMBERING, type LineNumbering } from './lib/storage/lineNumbering';
   import { loadFoldMarks, saveFoldMarks } from './lib/storage/foldMarks';
   import { printMarkup } from './lib/storage/printMarkup.svelte';
-  import { snapshots, loadSnapshots, readSnapshot } from './lib/storage/snapshots.svelte';
   import { commentsInPane, changesInPane, markupAttrs, setShowChanges, setShowComments } from './lib/storage/markup.svelte';
   import { loadDocumentLanguage, saveDocumentLanguage, odfFromLanguage, type DocumentLanguage } from './lib/storage/documentLanguage';
   import { setTableLanguage } from './lib/storage/tableOptions.svelte';
@@ -1071,29 +1070,6 @@
     }
   }
 
-  // The versions the autosave keeps aside, and the reader's label for one.
-  void loadSnapshots();
-  function snapshotLabel(at: number): string {
-    return new Date(at).toLocaleString(locale(), { dateStyle: 'short', timeStyle: 'short' });
-  }
-
-  // Put an earlier version's text back. The page setup, the styles and the zones
-  // belong to the open document, so only the text is replaced.
-  async function handleRestoreSnapshot(at: number) {
-    exportMenuOpen = false;
-    if (!editor || !confirm(t().dialogs.confirmRestore(snapshotLabel(at)))) return;
-    const json = await readSnapshot(at);
-    if (!json) {
-      alert(t().dialogs.snapshotGone);
-      void loadSnapshots();
-      return;
-    }
-    loadContent(json as Content);
-    documentEpoch++;
-    resetHistory();
-    editor.commands.focus();
-  }
-
   function handleForgetRecent() {
     forgetRecentFiles();
     recentFiles = [];
@@ -1371,8 +1347,6 @@
       recentFiles={recentFiles}
       onOpenRecent={(id) => { const f = recentFiles.find((r) => r.id === id); if (f) void handleOpenRecent(f); }}
       onForgetRecent={handleForgetRecent}
-      snapshots={snapshots().map((at) => ({ at, label: snapshotLabel(at) }))}
-      onRestoreSnapshot={(at) => void handleRestoreSnapshot(at)}
       onExportPdf={handleExportPdf}
       onPrintPdf={handlePrintPdf}
       onPrint={handlePrint}
@@ -1510,14 +1484,6 @@
                   <span class="theme-option-hint">{t().app.clearRecentFiles}</span>
                 </button>
               {/if}
-              {#if snapshots().length}
-                <div class="theme-heading">{t().app.versions}</div>
-                {#each snapshots() as at (at)}
-                  <button class="theme-option" onclick={() => handleRestoreSnapshot(at)} role="menuitem">
-                    <span class="recent-name">{snapshotLabel(at)}</span>
-                  </button>
-                {/each}
-              {/if}
               <button class="theme-option" onclick={() => { exportMenuOpen = false; passwordSetOpen = true; }} role="menuitem">
                 <span>{t().password.menu}</span>
                 {#if docProtected}<span class="theme-option-hint">{t().password.menuOn}</span>{/if}