feat(disney): add media kit page for disney experience summary

[falgon]

概要

• disney_experience_summary 向けの Media Kit ページを追加
• 体験録一覧のヘッダから Media Kit へ遷移できる導線を追加
• Media Kit 本文を Markdown 管理にして、更新しやすい構成にした

主な変更

• contents/disney_experience_summary/media_kit.md を追加（営業向け説明本文）
• contents/pages/disney_experience_summary/media-kit.html を追加（公開ページ）
• src/Rules/DisneyExperienceSummary.hs
  • Media Kit 用 markdown の snapshot 対象追加
  • disney_experience_summary/media-kit.html 生成ルール追加
  • 互換リダイレクト media_kit.html -> media-kit.html を追加
• contents/pages/disney_experience_summary/jp.html
  • 一覧ヘッダに Media Kit リンク追加
• contents/scss/disney_experience_summary_only.scss
  • Media Kit 向けスタイル追加
  • タイトル右上メタ領域のレイアウト調整（モバイル含む）

確認

• make format
• make check（既存 warning のみ）
• make test

Refs: #962

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	28.6%	593 / 2073
🔵	Statements	28.6%	611 / 2136
🔵	Functions	30.81%	114 / 370
🔵	Branches	20.19%	208 / 1030

File Coverage

No changed files found.

Generated in workflow #942 for commit a4d5ca9 by the Vitest Coverage Report Action

[github-actions]

Haskell Test Coverage Report

Generating combined coverage report.
Summary combined coverage report:
 78% expressions used (1005/1287)
 55% boolean coverage (5/9)
      50% guards (3/6), 3 always True
      66% 'if' conditions (2/3), 1 always True
     100% qualifiers (0/0)
 77% alternatives used (34/44)
 67% local declarations used (38/56)
 50% top-level declarations used (126/251)
The combined coverage report is available at
/Users/runner/work/roki-web/roki-web/.stack-work/install/aarch64-osx/c8bd8cc889b4268cdf5e7d0b073c5450e5447f77efaf84c8174147ae1a288879/9.6.6/hpc/combined/custom/hpc_index.html.

_{Generated by stack hpc report}

[kiirotori]

• 
• Build log
• Preview build with this PR (9efc097)

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• ☁️ Storage Free space 1.77 GiB 11.78%
• 📂 0 B CI_WORK/GitHubActions/roki-web

[kiirotori]

• 
• Build log
• Preview build with this PR (a4d5ca9)

---

more info

• ☁️ Storage Free space 7.09 GiB 47.29%
• 📂 132.27 MiB CI_WORK/GitHubActions/roki-web