Mark the file the folder download is on

During "Download all to a folder" the recipient saw only the file name
under the progress bar. The file's row in the list now shows the loading
indicator while it is on its way, and the list scrolls that row into
view, so a run through hundreds of files can be followed in the list.
The row is scrolled rather than the indicator, which is still hidden
when the run moves on to the file.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/Browser/ShareFlowTest.php

@@ -313,3 +313,40 @@ test('a long file list scrolls on its own and keeps the download buttons on the
         ->assertScript("[...document.querySelectorAll('[data-md-button]')].filter((button) => button.offsetParent !== null && button.textContent.trim().toLowerCase().startsWith('download all')).every((button) => button.getBoundingClientRect().bottom <= window.innerHeight)")
         ->assertNoJavaScriptErrors();
 });
+
+test('the folder download marks the file it is on and scrolls the list to it', function () {
+    $share = app(ShareService::class)->createShare(collect(range(1, 40))->map(fn (int $number): array => [
+        'file' => UploadedFile::fake()->createWithContent("file-{$number}.txt", "file {$number}"),
+        'relativePath' => null,
+    ])->all());
+    $last = $share->files->last();
+
+    $page = ready(visit(route('share.download', $share, false))->resize(1280, 800));
+
+    // Every file but the last is already in the folder, and the last one's request never answers,
+    // so the run stays on it.
+    $page->script("(async () => {
+        const root = await navigator.storage.getDirectory();
+        for await (const name of root.keys()) { await root.removeEntry(name, { recursive: true }); }
+        for (let number = 1; number < 40; number++) {
+            const writable = await (await root.getFileHandle(`file-\${number}.txt`, { create: true })).createWritable();
+            await writable.write(`file \${number}`);
+            await writable.close();
+        }
+        window.showDirectoryPicker = () => Promise.resolve(root);
+        window.fetch = () => new Promise(() => {});
+        Alpine.\$data(document.querySelector('[data-test=download-to-folder]')).supported = true;
+    })()");
+
+    $page->click('[data-test="download-to-folder"]');
+
+    $page->assertScript("[...document.querySelectorAll('[data-test=file-downloading]')].filter((mark) => mark.offsetParent !== null).length === 1")
+        ->assertScript("(() => {
+            const mark = [...document.querySelectorAll('[data-test=file-downloading]')].find((mark) => mark.offsetParent !== null);
+            const row = mark.closest('[data-md-list-item]');
+            const list = document.querySelector('[data-test=share-file-list]').getBoundingClientRect();
+            const rect = row.getBoundingClientRect();
+            return row.textContent.includes('{$last->original_name}') && rect.top >= list.top - 1 && rect.bottom <= list.bottom + 1;
+        })()")
+        ->assertNoJavaScriptErrors();
+});