[Task] `ToggleSwitch` internal button defaults to submit inside forms

[acbreton]

Summary

Primer::Alpha::ToggleSwitch renders a <button> without type. Inside a <form>, it defaults to type="submit" and can trigger Chrome “required field” validation tooltips on other empty inputs.

Repro

1. Put ToggleSwitch inside a form with an empty required field.
2. Click the toggle.
3. Chrome shows native validation tooltips / acts like a submit.

Fix

Render the track button with type="button" and add a test for .ToggleSwitch-track[type="button"].

References

Screen.Recording.2026-02-12.at.12.27.06.PM.mov

[michaellinhq]

Hi, I reviewed '[Task] ToggleSwitch internal button defaults to submit inside forms' and can start immediately. I can deliver a first usable version quickly and iterate based on your feedback. If this scope still matches your priority, I can proceed right away.