fix: Handle SRT files with BOM by using utf-8-sig encoding

merge_srt.py

@@ -1,7 +1,7 @@
 import sys
 
 def parse_srt(filename):
-    with open(filename, 'r', encoding='utf-8') as f:
+    with open(filename, 'r', encoding='utf-8-sig') as f:
         content = f.read().strip()
     blocks = content.split('\n\n')
     entries = []