WIP: feat(ui-tars): support remote operators

[ZhaoHeh]

Summary

Checklist

• Added or updated necessary tests (Optional).
• Updated documentation to align with changes (Optional).
• Verified no breaking changes, or prepared solutions for any occurring breaking changes (Optional).
• My change does not involve the above items.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 297 lines in your changes missing coverage. Please review.

Project coverage is 5.47%. Comparing base (f9ddab2) to head (a3c9ff4).

Files with missing lines	Patch %	Lines
apps/ui-tars/src/main/agent/proxyClient.ts	0.00%	167 Missing ⚠️
apps/ui-tars/src/main/agent/operator.ts	0.00%	99 Missing ⚠️
...operators/browser-operator/src/browser-operator.ts	0.00%	31 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##            main    #622      +/-   ##
========================================
- Coverage   5.64%   5.47%   -0.18%     
========================================
  Files        292     293       +1     
  Lines       9399    9696     +297     
  Branches    1805    1860      +55     
========================================
  Hits         531     531              
- Misses      8794    9091     +297     
  Partials      74      74              

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