🧪 Add tests for missing createStore validation

[johnstrand]

🎯 What: Added missing validation tests for invalid initialState arguments passed to createStore.
📊 Coverage: The test suite now explicitly tests passing null, undefined, arrays, strings, numbers, and booleans to createStore, and expects an error to be thrown. It also includes a valid happy path test.
✨ Result: Test coverage improved, which helps prevent future regressions related to invalid store initialization types. Also added jest framework configuration.

---

PR created automatically by Jules for task 12495821062522090397 started by @johnstrand

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.

[johnstrand]

@jules - We've got some merge conflicts that need dealt with

[google-labs-jules]

@jules - We've got some merge conflicts that need dealt with

I have resolved the merge conflicts with the master branch and ensured everything is working correctly.