chore(web): add enterprise dev proxy support

[hyoban]

Important

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2. Ensure there is an associated issue and you have been assigned to it
3. Use the correct syntax to link this PR: Fixes #<issue number>.

Summary

Follow #33371

Screenshots

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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 doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran make lint && make type-check (backend) and cd web && pnpm exec vp staged (frontend) to appease the lint gods

[codecov]

Codecov Report

❌ Patch coverage is 95.31250% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.81%. Comparing base (8967ff3) to head (3a4d76d).

Files with missing lines	Patch %	Lines
web/plugins/dev-proxy/config.ts	93.33%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #35842   +/-   ##
=======================================
  Coverage   85.81%   85.81%           
=======================================
  Files        4459     4460    +1     
  Lines      209039   209098   +59     
  Branches    39072    39091   +19     
=======================================
+ Hits       179387   179442   +55     
- Misses      26481    26485    +4     
  Partials     3171     3171           

Flag	Coverage Δ
dify-ui	93.27% <ø> (ø)
web	86.77% <95.31%> (+<0.01%)	⬆️

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