Invited members have no Nextcloud credentials of their own — stream and
waveform endpoints now use the file uploader's NC credentials instead of
the current member's. Falls back to the current member if uploaded_by is
null.
The invite listing/info endpoints were comparing timezone-aware
expires_at values against naive datetime.now(), causing a TypeError (500).
Fixed by using datetime.now(timezone.utc) throughout bands.py and
invites.py.
Also removes leftover debug logging from versions.py.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>