test(scanner): add comprehensive comic metadata extraction tests
Test coverage for multi-format comic archive metadata extraction:
Format-specific tests:
- TestExtractZipMetadata - .cbz (ZIP) with ComicInfo.xml
- TestExtractZipMetadataWithoutComicInfo - Fallback behavior
- TestExtractTarMetadata - .cbt (TAR) archives
- TestExtractTarGzMetadata - .tar.gz (gzipped TAR)
Integration tests:
- TestExtractComicMetadata - Router function tests
- TestIsImageFile - Image detection validation
Helper functions:
- createTestCBZ, createTestCBT, createTestTarGz - Create test archives
- Uses image/png package for valid test images
Tests cover:
- Metadata extraction (title, series, issue, publisher, writer)
- Cover image extraction with format validation
- Fallback behavior when metadata missing
- Error handling for invalid/corrupted archives
All tests use t.TempDir() for automatic cleanup and follow
project testing patterns (table-driven tests, t.Run(), etc).
john-okeefe
9238fad8d5