Enhance AniList character dictionary sync and subtitle features (#15)

src/shared/video-extensions.ts

@@ -0,0 +1,17 @@
+export const VIDEO_EXTENSIONS = new Set([
+  'mkv',
+  'mp4',
+  'avi',
+  'webm',
+  'mov',
+  'flv',
+  'wmv',
+  'm4v',
+  'ts',
+  'm2ts',
+]);
+
+export function hasVideoExtension(value: string): boolean {
+  const normalized = value.trim().toLowerCase().replace(/^\./, '');
+  return normalized.length > 0 && VIDEO_EXTENSIONS.has(normalized);
+}