🎨 Palette: 날짜 범위 선택기 프리셋에 aria-pressed 추가

[seonghobae]

💡 What: 날짜 범위 선택기(Date Range Picker)의 프리셋 버튼(7d, 30d, 90d, ALL)에 aria-pressed 속성을 추가하고 테스트 코드를 보강했습니다.
🎯 Why: 스크린 리더 사용자가 현재 시각적으로 활성화(선택)되어 있는 프리셋이 무엇인지 정확히 인지할 수 있도록 접근성을 향상시키기 위함입니다.
📸 Before/After: 프리셋 버튼 렌더링 시 선택된 프리셋에는 aria-pressed="true", 선택되지 않은 프리셋에는 aria-pressed="false"가 부여됩니다. (Playwright 스크립트로 동작 확인 완료)
♿ Accessibility: 세그먼트 컨트롤/토글 버튼의 상태를 보조 기기에 명확하게 전달합니다. 100% 테스트 커버리지를 보장합니다.

---

PR created automatically by Jules for task 2030665716675493339 started by @seonghobae

[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.