The downloadAndSaveTelegramFile inner function only used the server-side
file path (e.g. "documents/file_42.pdf") or the Content-Disposition
header (which Telegram doesn't send) to derive the saved filename.
The original filename provided by Telegram via msg.document.file_name,
msg.audio.file_name, msg.video.file_name, and msg.animation.file_name
was never passed through, causing all inbound files to lose their
user-provided names.
Now downloadAndSaveTelegramFile accepts an optional telegramFileName
parameter that takes priority over the fetched/server-side name.
The resolveMedia call site extracts the original name from the message
and passes it through.
Closes#31768
Made-with: Cursor
da05395c2a