**Add Vitest support and migrate frontend tests**

- Added Vitest configuration (`vitest.config.mjs`) for frontend unit testing with a `jsdom` environment.
- Migrated and rewrote key frontend tests (`api.test.js`, `comiclist.test.js`, `comicreader.test.js`, `historytable.test.js`, `router.test.js`, `store.test.js`) to Vitest, improving maintainability.
- Removed `tsconfig.json` and related TypeScript loaders from `webpack` configurations (`webpack.dev.js`, `webpack.prod.js`).
- Adjusted `eslint.config.mjs` to support Vitest tests.
- Updated `package-lock.json` to include Vitest, test utilities (`jsdom`, `@vue/test-utils`), and other associated packages.
- Updated Nginx configuration for better compression on assets (`gzip` adjustments).
- Enhanced `entrypoint.sh` to include first-run library indexing (`--if-empty` argument).
- Simplified the `scan_comics` command with a dedicated test for empty database scans.

This transition improves testing workflows and backend/frontend synergy while removing unused TypeScript dependencies.

comic/tests/test_scan_command.py

@@ -22,6 +22,29 @@ def test_scan_indexes_nested_directories(comic_volume: Path, reader_user) -> Non
     assert book.page_count == 2
 
 
+@pytest.mark.django_db
+def test_scan_if_empty_scans_an_empty_database(comic_volume: Path) -> None:
+    make_cbz(comic_volume / 'issue.cbz', pages=1)
+
+    call_command('scan_comics', if_empty=True)
+
+    assert models.ComicBook.objects.count() == 1
+
+
+@pytest.mark.django_db
+def test_scan_if_empty_skips_when_books_already_exist(comic_volume: Path) -> None:
+    """Files added while the container was down are left to the cron scan."""
+    make_cbz(comic_volume / 'issue.cbz', pages=1)
+    call_command('scan_comics')
+
+    make_cbz(comic_volume / 'later.cbz', pages=1)
+    call_command('scan_comics', if_empty=True)
+    assert models.ComicBook.objects.count() == 1
+
+    call_command('scan_comics')
+    assert models.ComicBook.objects.count() == 2
+
+
 @pytest.mark.django_db
 def test_scan_runs_without_any_user(comic_volume: Path) -> None:
     """The command no longer needs a user, because statuses are created when a book is read."""