fix: ensure $store reads are properly transformed

[Rich-Harris]

Alternative to #12951

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[changeset-bot]

🦋 Changeset detected

Latest commit: 5fe5789

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[dummdidumm]

This approach doesn't work if you access store values before their corresponding variable is declared

Update: I was wrong, the whole thing doesn't become a source in that example, this works, too.

confused myself