[alchemist] improve UI

[StupidRepo]

marked as draft due to bug. see below.

this PR also updates library/util/Navigation.kt due to a weird bug with IME padding, hence why the PR is a draft.

i have tried messing around with removing .imePadding() from the modifiers list, as well as attempting to consume it before getting to alchemist's HomeScreen.kt, but no matter what I do it either results in the HomeScreen.kt's first box (in the scaffold) either not moving up enough or moving up too much.

the red background is applied to alchemist's HomeScreen.kt's first box, as a way of demonstrasting what is happening.

Image	Description
	This is what happens already by default.
	This is what I want to happen instead. You can actually get this to happen by turning your phone's screen off, then turning it on and unlocking the device. No idea why it fixes after doing this.

edit: still can't fix this bug - this is why i hate compose so much 🥀

[StupidRepo]

if i remove scaffolds everywhere (or ignore their padding value, at the very least), this still seems to happen?
@vayun-mathur any suggestions on how to fix?

[StupidRepo]

Details

screen-20260522-203445-1779478453014.mp4

(outdated, see comment below) demo

[StupidRepo]

another, updated demo (showing commit 0d24cea)

Details

screen-20260522-224319-1779486142967.mp4

Features added	Description
Item bar is on the bottom	Looks nicer!
Filters	Items can be filtered by the first letter of their name, using the 3 preset categories or a custom letter!
Discovery notifications	Makes it easier to tell what you've just discovered after successfully combining an item to make new items!
Initial item info page	Shows recipes that make the item. It also shows recipes the item is used in, providing the recipe's output items are unlocked.
Final indicator	Final items show a star in the bottom-right of their icon in the item bar!
Deletion indicator	Any placed items, that are dragged on the canvas, will trigger the item bar to turn red and display an X.
Discoveries counter	While the discovery counter can be seen in the achievements page, the counter above the item bar can also be glanced at for a quick indication of progress.

improved item details screen (showing commit 1412564)

Details