feat(archive): add MIME types and compound-extension aliases for archive formats

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/mime.js

@@ -31,6 +31,12 @@ const OUTPUT_MIME_TYPES = {
   snb: 'application/octet-stream',
   tcr: 'application/octet-stream',
   azw3: 'application/vnd.amazon.ebook',
+  zip: 'application/zip',
+  tar: 'application/x-tar',
+  'tar.gz': 'application/gzip',
+  'tar.bz2': 'application/x-bzip2',
+  '7z': 'application/x-7z-compressed',
+  'tar.7z': 'application/x-7z-compressed',
 };
 
 export async function detectInputMime(filePath) {
@@ -67,6 +73,9 @@ function normalizeFormat(format) {
   if (format === 'heif') return 'heic';
   if (format === 'azw3') return 'mobi';
   if (format === 'fb2') return 'xml';
+  if (format === 'tar.gz') return 'gz';
+  if (format === 'tar.bz2') return 'bz2';
+  if (format === 'tar.7z') return '7z';
   return format;
 }