feat(routing): router group + private router 적용

[minsgy]

💡 왜 PR을 올렸나요?

• 모든 페이지의 RouterGroup을 적용했습니다.
• root template 의존성을 삭제하였습니다.
• Private Folder를 사용했습니다.

💁 무엇이 어떻게 바뀌나요?

• 디자인 레퍼런스:
• 관련 슬랙 링크:

💬 리뷰어분들께

• 컴포넌트 배럴패턴 쓰면 서버컴포넌트 관련한 에러가 발생하니 조심하십쇼 ㅠ

[codecov-commenter]

Codecov Report

Attention: 351 lines in your changes are missing coverage. Please review.

Comparison is base (2440daa) 0.08% compared to head (36d8f85) 0.08%.

Files	Patch %	Lines
...rc/app/(AppBarHeader)/_components/Appbar/index.tsx	0.00%	116 Missing ⚠️
src/app/layout.tsx	0.00%	24 Missing ⚠️
...nents/OnboardingBottomsheet/OnboardingCarousel.tsx	0.00%	17 Missing ⚠️
src/common/components/BackHeader/index.tsx	0.00%	13 Missing ⚠️
src/app/(AppBarHeader)/layout.tsx	0.00%	12 Missing ⚠️
src/app/(BackHeader)/layout.tsx	0.00%	12 Missing ⚠️
src/app/api/session/route.ts	0.00%	11 Missing ⚠️
next.config.js	0.00%	9 Missing ⚠️
src/common/providers/index.tsx	0.00%	9 Missing ⚠️
...der)/toks-main/_components/CategoryBottomSheet.tsx	0.00%	6 Missing ⚠️
... and 53 more

Additional details and impacted files

@@                Coverage Diff                 @@
##           release/routing    #389      +/-   ##
==================================================
- Coverage             0.08%   0.08%   -0.01%     
==================================================
  Files                  168     165       -3     
  Lines                 5937    5945       +8     
  Branches               168     165       -3     
==================================================
  Hits                     5       5              
- Misses                5932    5940       +8     

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