UI fixes

[traines-source]

• this resolves, if we agree that checking GTFS-provided colors for sufficient contrast is not in scope rn, WebUI contrast issue: white text on white line badge not visible #708
• this does very ugly things to at least temporarily fix the effect of accidentally tapping on the Departure/Arrival buttons or the date field when selecting a result from the From/To autocompletes. This is probably sth that needs fixing upstream in bits-ui, but I didn't yet manage to isolate the issue and spent far too much time on this already...

Lmk if you think that it makes sense to backport the changes from #705 and this PR to prima-mobile (since I still don't see any nice, straightforward way to share the components...)

[felixguendling]

checking GTFS-provided colors for sufficient contrast

Yes, that's out of scope. I would prefer if checks for this were added to GTFS validator tools. This is nothing we should try to fix in MOTIS or the UI as we're too late in the pipeline.

upstream in bits-ui, but I didn't yet manage to isolate the issue and spent far too much time on this already.

If it's easier to just roll our own components in some cases, it's fine to kick out bits-ui. It just comes in handy if it's exactly matching the use case. If it's not, it can become a burden instead of helping us.

Lmk if you think that it makes sense to backport the changes from #705 and this PR to prima-mobile (since I still don't see any nice, straightforward way to share the components...)

That would be amazing! :)