Release 2.3.0

A share can now hold a private text (a password, a key, a short note)
with its files or on its own. The upload page's new "Private text" card
takes up to 100 KB; the browser encrypts the text and sends it through
the same chunk pipeline as a file, flagged is_text on share_files, so it
gets the share's password, expiry, download limit and cleanup.

The recipient sees the text only after pressing "Show text", which
counts as their download, so a messenger link preview cannot use up a
share limited to one download. The text is left out of the file list,
the ZIP and the file counts; the admin dashboard marks shares that hold
one with "Text".

The website gains a Private text feature card and a fifth phone
screenshot; every screenshot is retaken.

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

tests/Feature/WebsiteTest.php

@@ -74,7 +74,7 @@ test('every file the pages, their stylesheets and the README refer to exists', f
 test('the screenshots are all there, for both themes and both widths', function () {
     $expected = collect([
         'desktop' => ['01-upload', '02-share-created', '03-qr-code', '04-download', '05-admin-dashboard', '06-admin-settings'],
-        'phone' => ['01-upload', '02-password', '03-download', '04-qr-code'],
+        'phone' => ['01-upload', '02-password', '03-download', '04-qr-code', '05-private-text'],
     ])->flatMap(fn (array $names, string $device): array => collect(['light', 'dark'])
         ->crossJoin($names, $device === 'desktop' ? [1600, 800] : [1080, 540])
         ->map(fn (array $shot): string => "{$device}/{$shot[0]}/{$shot[1]}-{$shot[2]}.webp")