Three small UX wins.
1. Auto-update: "Skip this version" button on the update modal.
Stores the dismissed version in localStorage; subsequent automatic
update-available events for the same version are silenced (banner
hidden, modal not opened). Manual "Check for updates" overrides the
skip so the user can change their mind. The flag is cleared once
the version is actually downloaded so a stale entry never masks a
future update. Skip button is hidden in the "ready to install"
state where it would not make sense.
2. addStreamer now validates against Twitch username rules
(4-25 chars, [a-zA-Z0-9_]). Previously bad input fell through to
the API and the user saw a silent "streamer not found" message
instead of being told the input was invalid.
3. Smart Queue Scheduler checkbox got a hover tooltip that explains
what enabling it actually does ("prefers shorter VODs and older
queue entries first"). Users were disabling it without knowing
what they were turning off.
DE + EN locale strings added for all three.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
