refactor(core): replace batch dependents map with batched changed atoms

[dmaskasky]

Summary

Batch.D was previously Map<Atom, Set<AtomDependent>>.
This allowed atom dependents to recompute without being mounted. There isn't an obvious reason to do so.
All tests pass after removing this functionality.

Dropped behavior

After this change, the following test would fail.
I don't think we should be update dependents of unmounted atoms.

it('recomputes dependents of unmounted atoms', () => {
  const a = atom(0)
  const bRead = vi.fn((get) => get(a))
  const b = atom(bRead)
  const c = atom((get) => get(b))
  const w = atom(null, (get, set) => {
    set(a, 1) // batch.D.set(a, new Set())
    get(c) // batch.D.get(a).add(b)
    set(a, 2) // topSortedReversed: [b, a]
    bRead.mockClear()
    // after this write function completes, flushBatch will recompute `a` and `b`
    // note: a and b are not mounted
  })
  const store = createStore()
  store.set(w)
  expect(bRead).toHaveBeenCalled()
})

Check List

• pnpm run fix:format for formatting code and docs

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commit: fe7c699

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Size Change: -527 B (-0.57%)

Total Size: 92.1 kB

Filename	Size	Change
./dist/esm/vanilla.mjs	4.22 kB	-103 B (-2.38%)
./dist/system/vanilla.development.js	4.31 kB	-101 B (-2.29%)
./dist/system/vanilla.production.js	2.17 kB	-51 B (-2.29%)
./dist/umd/vanilla.development.js	5.68 kB	-116 B (-2%)
./dist/umd/vanilla.production.js	2.86 kB	-39 B (-1.34%)
./dist/vanilla.js	5.56 kB	-117 B (-2.06%)

ℹ️ View Unchanged

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./dist/umd/react.production.js	936 B
./dist/umd/react/utils.development.js	1.53 kB
./dist/umd/react/utils.production.js	1.01 kB
./dist/umd/utils.development.js	399 B
./dist/umd/utils.production.js	342 B
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Latest commit: fe7c699
Last updated: Jan 7, 2025 12:16pm (UTC)

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[dai-shi]

wow, this looks cool. I will have a closer look later.

[dai-shi]

Oh, yes! This is something I wan't comfortable with. Thanks for fixing it. This goes towards what I have in mind. I'd like to go further.

Is this now possible because of .x?

Anyway, merging this.