refactor(web): sync app context effects with jotai

[hyoban]

Summary

• Replaces the app context bootstrap useEffect hooks with a jotai-effect atom that syncs Zendesk fields and Amplitude identity from app-context atoms.
• Mounts the bootstrap sync once from CommonLayoutHydrationBoundary, shared by the authenticated common layouts.
• Adds jotai-effect as a frontend dependency and updates focused tests around app context bootstrap and common layout hydration.

Related issue: N/A

Screenshots

Before	After
N/A	N/A

Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This does not apply to typos!)
• I have added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I have updated the documentation accordingly.
• I ran pnpm --dir web test app/(commonLayout)/__tests__/hydration-boundary.spec.tsx context/__tests__/app-bootstrap-effects.spec.tsx --run and pnpm --dir web type-check.

From Codex

[codecov]

Codecov Report

❌ Patch coverage is 98.50746% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 85.39%. Comparing base (23b936a) to head (10b84c1).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
web/context/amplitude-identity-sync.ts	95.83%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #38570      +/-   ##
==========================================
+ Coverage   85.34%   85.39%   +0.05%     
==========================================
  Files        5016     5174     +158     
  Lines      266941   271378    +4437     
  Branches    50816    51906    +1090     
==========================================
+ Hits       227814   231742    +3928     
- Misses      34660    35169     +509     
  Partials     4467     4467              

Flag	Coverage Δ
cli	88.48% <ø> (?)
dify-ui	94.61% <ø> (ø)
web	84.84% <98.50%> (+<0.01%)	⬆️

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