Support pure fetch in OSD for streaming output.

[SuZhou-Joe]

Description

Issues Resolved

Screenshot

Testing the changes

Changelog

Check List

• All tests pass
  • yarn test:jest
  • yarn test:jest_integration
• New functionality includes testing.
• New functionality has been documented.
• Update CHANGELOG.md
• Commits are signed per the DCO using --signoff

[github-actions]

❌ Empty Changelog Section

The Changelog section in your PR description is empty. Please add a valid changelog entry or entries. If you did add a changelog entry, check to make sure that it was not accidentally included inside the comment block in the Changelog section.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 61.81%. Comparing base (6cf85af) to head (cdabe8b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/core/public/http/fetch.ts	0.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #9592   +/-   ##
=======================================
  Coverage   61.81%   61.81%           
=======================================
  Files        3825     3825           
  Lines       92058    92060    +2     
  Branches    14602    14603    +1     
=======================================
+ Hits        56902    56904    +2     
  Misses      31482    31482           
  Partials     3674     3674           

Flag	Coverage Δ
Linux_1	28.94% <0.00%> (-0.01%)	⬇️
Linux_2	56.37% <0.00%> (-0.01%)	⬇️
Linux_3	39.42% <0.00%> (+<0.01%)	⬆️
Linux_4	28.84% <0.00%> (-0.01%)	⬇️
Windows_1	28.96% <0.00%> (-0.01%)	⬇️
Windows_2	56.33% <0.00%> (-0.01%)	⬇️
Windows_3	39.42% <0.00%> (-0.01%)	⬇️
Windows_4	28.84% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.