fix(admin): 统一剧集上传格式与提示文案

Co-authored-by: Cursor <cursoragent@cursor.com>

src/locales/en.ts

@@ -537,7 +537,7 @@ export default {
     retry: 'Retry',
     retryAll: 'Retry all',
     remove: 'Remove',
-    hint: 'Supports MP4 / MOV / MKV / WEBM, max 500MB each; up to 2 files in parallel.',
+    hint: 'Supports MP4 / MOV / MKV / WEBM, max 500MB each; multi-select allowed, 2 upload in parallel, the rest queue automatically.',
     invalidType: 'Only MP4, MOV, MKV, WEBM are allowed',
     oversize: 'File exceeds 500MB and was not queued',
     overallProgress: 'Overall progress',