This PR replaces the `.value` getter for the atom with `.get()`
### Change Type
- [x] `major` — Breaking change
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Co-authored-by: David Sheldrick <d.j.sheldrick@gmail.com>
It tried to get out but we're dragging it back in.
This PR brings [signia](https://github.com/tldraw/signia) back into
tldraw as @tldraw/state.
### Change Type
- [x] major
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Co-authored-by: David Sheldrick <d.j.sheldrick@gmail.com>