**Replace Flake8 with Ruff, refactor type hints, and enhance archive processing logic**

- Removed `flake8` and `flake8-annotations` from dependencies, replaced by `ruff` for linting.
- Introduced cleaner type hinting and modern Python annotations (PEP 604 style) across multiple modules.
- Moved archive processing to a dedicated helper (`comic.archives`) for improved maintainability.
- Updated and simplified logic for archive file retrieval, directory cleaning, and user access validation.
- Improved error handling and added support for user classification restrictions in API responses.

comic/tests/test_processing.py

@@ -0,0 +1,48 @@
+"""Tests for the filesystem reconciliation in comic.processing."""
+
+import pytest
+
+from comic import models
+from comic.processing import clean_directories, clean_files, generate_directory
+from comic.tests.factories import make_cbz
+
+
+@pytest.mark.django_db
+def test_clean_directories_adds_new_and_removes_stale(comic_volume, reader_user) -> None:
+    parent = models.Directory.objects.create(name='Series')
+    models.Directory.objects.create(name='Gone', parent=parent)
+    (comic_volume / 'Series' / 'New').mkdir(parents=True)
+
+    clean_directories(models.Directory.objects.filter(parent=parent), comic_volume / 'Series', parent)
+
+    names = set(models.Directory.objects.filter(parent=parent).values_list('name', flat=True))
+    assert names == {'New'}
+
+
+@pytest.mark.django_db
+def test_clean_files_ignores_unsupported_extensions(comic_volume, reader_user) -> None:
+    directory = models.Directory.objects.create(name='Series')
+    target = comic_volume / 'Series'
+    target.mkdir(parents=True)
+    make_cbz(target / 'issue.cbz', pages=2)
+    (target / 'notes.txt').write_text('not a comic')
+
+    clean_files(models.ComicBook.objects.filter(directory=directory), reader_user, target, directory)
+
+    books = list(models.ComicBook.objects.filter(directory=directory))
+    assert [book.file_name for book in books] == ['issue.cbz']
+    assert books[0].page_count == 2
+    assert models.ComicStatus.objects.filter(user=reader_user).count() == 1
+
+
+@pytest.mark.django_db
+def test_generate_directory_creates_missing_statuses(comic_volume, reader_user) -> None:
+    directory = models.Directory.objects.create(name='Series')
+    target = comic_volume / 'Series'
+    target.mkdir(parents=True)
+    make_cbz(target / 'issue.cbz', pages=1)
+
+    entries = generate_directory(reader_user, directory)
+
+    assert [entry.title for entry in entries] == ['issue.cbz']
+    assert models.ComicStatus.objects.filter(user=reader_user, comic=entries[0]).exists()