`prefer-writable-derived` should not apply to store

[tipy01]

Before You File a Bug Report Please Confirm You Have Done The Following...

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.

What version of ESLint are you using?

9.36.0

What version of eslint-plugin-svelte are you using?

3.12.4

What did you do?

Configuration

I let the default for prefer-writable-derived

// myStore store is on an object (not a primitive)

	// passing directly from Svelte store to state via derived does not works !!!
	// eslint-disable-next-line svelte/prefer-writable-derived
	let sta = $state($myStore);
	$effect(() => {
		sta = $myStore;
	});

What did you expect to happen?

Because deep reactivity on store (store on non primitive of course) require to be inventive (sveltejs/svelte#14772 (comment)) it is not so obvious that we should prefer using derived.

Personally I prefer much more the combination of a state and effect with a comment explaining why this should not be replaced with a derived.

I guess most of people still using stores are those who did not want to spend too much time during 4->5 migration turning their store to state because their store were complex objects, while primitive store are very easy to upgrade when not auto migrated by tooling.

So I think this rule could check if the initial value passed to $state begins with a $ sign and if so the rule does not apply.

What actually happened?

Prefer using writable $derived instead of $state and $effecteslint[svelte/prefer-writable-derived](https://sveltejs.github.io/eslint-plugin-svelte/rules/prefer-writable-derived/)

Link to GitHub Repo with Minimal Reproducible Example

https://svelte.dev/playground/ee8b98a1ac8a475c88bd45b4b30a443a?version=5.39.6

Additional comments

No response