widget configuration suggestions

- add key-bindings for convenience
- [ ] [Inkscape's scaling shortcuts](https://inkscape.org/doc/keys.html#idm1721) would be very appreciated
- hold `CTRL` to preserve aspect ratio
- hold `SHIFT` to transform symmetrically (about the object center, instead of about the opposite point)
- hold `ALT` to scale by integer ratios (e.g. 2x, 3x, 1/2x, 1/3x, etc)
- something for "fit to contents" would be handy (e.g. so you can make a video/image widget show the full frame without padding/cropping)
- [ ] some of [Inkscape's movement shortcuts](https://inkscape.org/doc/keys.html#idm1626) would also be useful
- hold `CTRL` to restrict movement to horizontal or vertical
- hold `SHIFT` to temporarily disable snapping (once snapping is re-introduced)
- press `c` to drop a copy of the thing being moved
- these could potentially be handled via cockpit actions
- [ ] backspace/delete while a widget is selected to delete it
- [ ] `h`/`v` for vertical/horizontal flip
- useful at least for the video widget
- [ ] `ESC` to exit edit mode (when not configuring a widget)
- [ ] `e` to enter edit mode
- [x] change configuration icon from vertical dots to a cog (`mdi-settings`)
- I knew that I was looking for an icon in the top right corner, and the current one still took me multiple attempts to find, it's almost invisible and isn't obvious what it's for
- colour pickers
- [ ] widgets with a colour selector should ideally offer an on-screen colour picker as a colour selection option
- this would help people trying to copy a particular theme/setup from another software / from an image
- [ ] support [more intuitive colour pickers](https://bottosson.github.io/posts/colorpicker/#introducing-two-new-color-spaces%3A-okhsv-and-okhsl)
- standard widget selection
- [ ] highlight the selected widget in the 'current widgets' list, and allow selections to persist if you click on a widget (or click it in the current widgets list)
- #844
- [ ] ideally the widget selector should show previews of the widgets, like the mini-widget selector does, or at least some relevant icon so they're easier to tell apart without reading the names
- [x] Add ⠿symbols to the left of each widget in the "Current widgets" when hovering over the name, and a margin when not hovering
- it's currently not obvious that it's possible to reorder them by dragging, and that symbol is pretty standard (it's used by at least GitHub and Notion)
- it's probably also worth adding a ↕ symbol to the left of the "current widgets" heading, to make that extra obvious
- I think hovering over a widget name in the list should also highlight it in the interface, and clicking on the name should open the configuration options (instead of doing nothing unless you drag)
- [x] stop treating the mini-widget trash as a persistent collection
- I don't want or need to be able to re-order the mini-widgets that I've already deleted, and I can't get widgets back out of that box so it's not helpful to show them there
- [x] allow mini-widgets to be configured from edit mode
- a click is not the same as a drag, and normal widgets are configured through edit mode so it's weird that mini-widgets are only configurable when _not_ in edit mode
- if that's not possible, at least grey them out / do something to make it obvious that they're not configurable when that's the case
- [ ] improve regular vs mini-widget display switching
- having separate buttons/cards is confusing, and makes it seem like they're items that can be dragged or something
- we could have something that looks more like tabs
- e.g. a card with a background only around the currently active tab

- or a diagonal, with the inactive one darker and in the bottom left

- we could combine them to a single button that changes text depending on what's currently active
- e.g. "Configure regular widgets" ↔ "Configure mini widgets"
- other "action" buttons (e.g. for configuring individual widgets or views) seem to have much smaller corner radii, so perhaps that's styling we want to maintain as a visual aid for what is an "item" vs a "button"
- perhaps the whole bottom left corner could be turned into a big button
- [ ] improve edit mode side-bar to focus on active/useful components
- relevant discussion in #699

No files, tests, or entry points are named. Begin by separating the requested widget configuration, keyboard shortcut, color picker, selection, and edit-mode changes, then locate the existing widget and edit-mode UI before choosing one scoped item; done should be defined by that item's specific interaction and its related UI behavior.

Written by the indexing model from the issue text.