Release v0.2.2 - Display file checksums in UI

Features:
- Add SHA256 column to admin product versions table
- Display file hash in customer account downloads section
- Style checksum file upload field consistently with package upload

Changes:
- Admin versions table shows truncated hash with full hash on hover
- Customer downloads show hash with shield icon indicator
- Updated German translations

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/Frontend/AccountController.php

@@ -129,6 +129,7 @@ final class AccountController
                             ),
                             'release_notes' => $version->getReleaseNotes(),
                             'released_at' => $version->getReleasedAt()->format(get_option('date_format')),
+                            'file_hash' => $version->getFileHash(),
                         ];
                     }
                 }