Give an audio file its own cleanup rules, written for subtitles

Cleaning up a dictation and cleaning up a file are not the same job, and until
now they shared one prompt. A dictation is read afterwards, so dropping a
filler and tightening a sentence is a favour. A file becomes an SRT, and there
the same favour is damage: the viewer hears the words while the line is on
screen, so a word that was said and is not written is noticed, and a phrase
pulled onto the line above is on screen before it is spoken.

So the file path gets its own system prompt. It says what the text is and what
it is for, and it spends its room on the one repair only context can make: the
word the transcriber misheard. Speech models fail phonetically on names, and
somebody talking about Anthropic said "Claude", not "cloud". The lines stay
where they are, nothing is shortened, nothing is turned into an abbreviation,
and the filler words stay because they were said out loud.

The glossary and the timestamp rule are appended as before, so a name listed
under Cleanup rules still reaches this prompt, and a timestamped run still gets
told to leave the stamps alone. The dictation prompt is untouched, and so are
the meeting and agent paths.

Cleanup rules now has a tab each. An untouched prompt is still stored empty, so
switching the interface language keeps switching the prompt language with it.

README.md

@@ -106,7 +106,8 @@ second one stacks above the first while both are up.
   for.
 - **Audio and video files** run through the same models under Settings → Audio
   file, optionally with `[mm:ss]` timestamps, chunked through ffmpeg when long,
-  and saved as `.txt` or as `.srt` subtitles.
+  and saved as `.txt` or as `.srt` subtitles; their cleanup follows its own rules,
+  written for subtitles, so the lines keep their place and nothing is shortened.
 - **History** of every dictation under Settings → History, with a size limit and
   right-click to delete.
 - **Turkish and English interface**, following the system locale by default.