fix: clear() deletes chapter/subtitle files + persist subtitle_files

Bug fixes from full codebase review:
- clear() with DELETE_FILE_ON_TRASHCAN now also deletes chapter_files
  and subtitle_files, not just the primary filename
- _PERSISTED_DOWNLOAD_FIELDS now includes 'subtitle_files' so subtitle
  file info survives app restart

Tests:
- Added test_subtitle_lang_list_with_region_variant_input (zh-Hans)
- Added test_subtitle_lang_list_dedup_region_variant (pt-BR)

app/tests/test_dl_formats.py

@@ -134,6 +134,23 @@ class DlFormatsTests(unittest.TestCase):
         self.assertEqual(_normalize_subtitle_language(""), "en")
         self.assertEqual(_normalize_subtitle_language("  "), "en")
 
+    def test_subtitle_lang_list_with_region_variant_input(self):
+        """zh-Hans should expand to include zh base and zh-CN, zh-TW, etc."""
+        from app.dl_formats import _subtitle_lang_list
+        result = _subtitle_lang_list("zh-Hans", include_orig=True)
+        self.assertEqual(result[0], "zh-Hans")  # original input first
+        self.assertIn("zh", result)              # base language fallback
+        self.assertIn("zh-CN", result)           # regional variant
+        self.assertIn("zh-orig", result)         # orig suffix for auto-captions
+
+    def test_subtitle_lang_list_dedup_region_variant(self):
+        """pt-BR should not duplicate pt-BR in the variant expansion."""
+        from app.dl_formats import _subtitle_lang_list
+        result = _subtitle_lang_list("pt-BR", include_orig=True)
+        self.assertEqual(result.count("pt-BR"), 1)  # no duplicate
+        self.assertIn("pt", result)                   # base language fallback
+        self.assertIn("pt-PT", result)                # other regional variant
+
 
 if __name__ == "__main__":
     unittest.main()

app/ytdl.py

@@ -328,6 +328,7 @@ _PERSISTED_DOWNLOAD_FIELDS = (
     "filename",
     "size",
     "chapter_files",
+    "subtitle_files",
 )
 
 
@@ -1494,11 +1495,23 @@ class DownloadQueue:
                 continue
             if self.config.DELETE_FILE_ON_TRASHCAN:
                 dl = self.done.get(id)
-                try:
-                    dldirectory, _ = self.__calc_download_path(dl.info.download_type, dl.info.folder)
-                    os.remove(os.path.join(dldirectory, dl.info.filename))
-                except Exception as e:
-                    log.warning(f'deleting file for download {id} failed with error message {e!r}')
+                dldirectory, _ = self.__calc_download_path(dl.info.download_type, dl.info.folder)
+                # Delete the primary downloaded file
+                files_to_delete = [dl.info.filename]
+                # Also delete chapter files and subtitle files
+                for cf in getattr(dl.info, 'chapter_files', []) or []:
+                    if isinstance(cf, dict) and cf.get('filename'):
+                        files_to_delete.append(cf['filename'])
+                for sf in getattr(dl.info, 'subtitle_files', []) or []:
+                    if isinstance(sf, dict) and sf.get('filename'):
+                        files_to_delete.append(sf['filename'])
+                for filename in files_to_delete:
+                    if not filename:
+                        continue
+                    try:
+                        os.remove(os.path.join(dldirectory, filename))
+                    except Exception as e:
+                        log.warning(f'deleting file {filename} for download {id} failed with error message {e!r}')
             self.done.delete(id)
             await self.notifier.cleared(id)
         return {'status': 'ok'}