Mantine's multiselect does not let you edit the search box with mouse, paste into it, etc. Normal select is fine.
I can't remember why I made Lora etc multiselects, but everything seems to work with normal selects, so I've change to that.
- `isLoading` - now `true` *only* on first load
- added `isFetching` - `true` whenever gallery images are fetching
- on first load, show a spinner instead of skeletons. this prevents an awkward flash of skeletons into empty gallery when the gallery doesn't have enough images to fill it.
- removed `imageCategoriesChanged` listener, bc now on app start, both images and assets will be populated. leaving this in caused jank flashes of skeletons when switching gallery tabs when gallery doesn't have images to load
taking the coward's way out on this and just fetching 100 images & 100 assets on app start...
- add `appStarted` action, dispatched once on mount in App.tsx. listener fetches 100 images & 100 assets
- fix bug with selectedBoardId & assets tab
The shift key listener didn't catch pressed when focused in a textarea or input field, causing jank on slider number inputs.
Add keydown and keyup listeners to all such fields, which ensures that the `shift` state is always correct.
Also add the action tracking it to `actionsDenylist` to not clutter up devtools.
There was a props on IAISlider to make the input component readonly - I didn't know this existed and at some point used a component with that prop as a template for other sliders, copying the flag over.
It's not actually used anywhere, so I removed the prop entirely, enabling the number inputs everywhere.
