feat: drag-to-reorder dashboard sections

[Death-Watcher]

Description

Enable drag-to-reorder for dashboard sections using the existing useSettingsSortable hook:

• Drag handle — Each section gets a grip handle (ChevronGripIcon) on the left side. Hover reveals the handle; cursor changes to grab/grabbing.
• Drop indicators — Translucent drop-line elements appear between sections during a drag, with the active slot highlighted.
• Persistence — The new section order is saved to the sectionOrder preference immediately on reorder via setPreference.

Type of Change

• New feature

How to Test

• npm install && npm run build
• Deploy to Spicetify
• Open Listening Stats dashboard
• Hover any section — the grip handle should appear
• Drag a section up or down — drop lines should indicate the target position
• Refresh the page — the custom order should persist

Checklist

• Tested locally with npm run build (no errors)
• All 1188 tests pass (npx vitest run)
• TypeScript strict (npx tsc --noEmit)
• No sensitive data included

Files Changed

• src/app/App.tsx — useSettingsSortable integration, drag UI rendering, data attributes
• src/app/styles.css — .dashboard-* classes for drag handle, drop lines, section layout

[Xndr2]

Not a needed front end feature. Dragging works in the settings menu, which feels more user friendly. Making the dashboard overall less cluttered.
You can update the settings dragging if you like