enhance: パッケージのビルド・Watchをtsdownに統一

[kakkokari-gtyih]

What

wip

Why

• 自前でwatch処理を書いているが、これをrolldown側でハンドリングしてくれるようになるため効率的＋コードベースがすっきりする
• 自前でTypescript Declaration Fileのビルド処理を書いているが、これをtsdown側でハンドリングしてくれるようになるため効率的＋コードベースがすっきりする
• frontend-sharedは現状frontendとfrontend-embedから直接見ているのでビルドの必要が無い

Additional info (optional)

Checklist

• Read the contribution guide
• Test working in a local environment
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests

[github-actions]

Backend memory usage comparison

Before GC

Metric	base (MB)	head (MB)	Diff (MB)	Diff (%)
VmRSS	306.00 MB	308.51 MB	+2.50 MB	+0.81%
VmHWM	306.00 MB	308.51 MB	+2.50 MB	+0.81%
VmSize	23102.02 MB	23104.96 MB	+2.94 MB	+0.01%
VmData	1368.09 MB	1370.88 MB	+2.78 MB	+0.20%

After GC

Metric	base (MB)	head (MB)	Diff (MB)	Diff (%)
VmRSS	306.03 MB	308.51 MB	+2.48 MB	+0.81%
VmHWM	306.03 MB	308.51 MB	+2.48 MB	+0.81%
VmSize	23102.02 MB	23104.96 MB	+2.94 MB	+0.01%
VmData	1368.09 MB	1370.88 MB	+2.78 MB	+0.20%

After Request

Metric	base (MB)	head (MB)	Diff (MB)	Diff (%)
VmRSS	306.26 MB	308.79 MB	+2.52 MB	+0.82%
VmHWM	306.26 MB	308.82 MB	+2.55 MB	+0.83%
VmSize	23102.02 MB	23104.96 MB	+2.94 MB	+0.01%
VmData	1368.01 MB	1370.88 MB	+2.86 MB	+0.20%

See workflow logs for details

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.91%. Comparing base (985de91) to head (e40d7a2).

Additional details and impacted files

@@             Coverage Diff              @@
##           develop   #17326       +/-   ##
============================================
+ Coverage    24.85%   85.91%   +61.06%     
============================================
  Files         1150        2     -1148     
  Lines        38847      213    -38634     
  Branches     10785       38    -10747     
============================================
- Hits          9654      183     -9471     
+ Misses       23424       29    -23395     
+ Partials      5769        1     -5768     

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