🎨 Palette: Add accessibility and tooltips to NodeModulesSection header

[acebytes]

💡 What: Added accessibility labels, values, traits, and a help tooltip to the collapsible NodeModulesSection header.
🎯 Why: To clearly indicate to VoiceOver users that the header acts as an expandable/collapsible button and report its current state. The tooltip provides mouse hover context.
📸 Before/After: Visuals remain unchanged, but VoiceOver now correctly reads the button state and label, and hovering over the area shows a tooltip.
♿ Accessibility: Added accessibilityLabel, accessibilityValue, accessibilityAddTraits, and help modifiers.

---

PR created automatically by Jules for task 13643687145363839748 started by @acebytes

[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.

[acebytes]

Heads-up before this gets rebased: the diff removes the three existing .jules/palette.md entries (Clickable List Rows / Icon-only Controls / Empty States in Process Lists) and replaces them with the new NodeModulesSection-header entry. That's because this branch was based on an older palette.md. Rebasing onto current main will cause an add/add conflict — the right resolution is to append the new entry to the existing three, not replace them.

The Swift code change (.accessibilityLabel / .accessibilityValue / .accessibilityAddTraits(.isButton) / .help on the disclosure header) looks correct and aligns with the documented 'Accessibility Modifiers on Icon-only Controls' learning.

[google-labs-jules]

Heads-up before this gets rebased: the diff removes the three existing .jules/palette.md entries (Clickable List Rows / Icon-only Controls / Empty States in Process Lists) and replaces them with the new NodeModulesSection-header entry. That's because this branch was based on an older palette.md. Rebasing onto current main will cause an add/add conflict — the right resolution is to append the new entry to the existing three, not replace them.

The Swift code change (.accessibilityLabel / .accessibilityValue / .accessibilityAddTraits(.isButton) / .help on the disclosure header) looks correct and aligns with the documented 'Accessibility Modifiers on Icon-only Controls' learning.

Thank you for the heads-up. I've updated the PR so that the new .jules/palette.md entry is appended to the existing file rather than replacing it to avoid merge conflicts.