Bug fixed: When a folder already contained the same episode token as
the source file (e.g. Show.S01E05.720p-4sf + s01e05.mkv), the episode
was inserted a second time producing Show.S01E05.720p.S01E05-4sf.
Root cause: The replace produced an identical string, the equality check
fell through to the suffix-insert branch which added the token again.
Fix: Use regex.test() first, then always apply the replacement when
an episode pattern exists in the folder name.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
