GH#265: Preserve Guzzle HTTP error responses

[superdav42]

Summary

• preserve PSR-18-style response semantics when request options select the Guzzle-compatible send() path
• disable Guzzle status-code exceptions while retaining timeout and redirect option translation
• cover 529 and representative 4xx responses through the SDK's typed response handling

Resolves #265

Testing

• vendor/bin/phpunit tests/unit/Providers/Http/HttpTransporterTest.php — 12 tests, 56 assertions
• vendor/bin/phpunit tests/unit/Providers/Http/Util/ResponseUtilTest.php — 9 tests, 18 assertions
• composer test:unit — 1,166 tests, 4,271 assertions
• composer lint — PHPCS 207 files; PHPStan 111 files, no errors
• composer validate --strict
• composer check-platform-reqs

Runtime Testing

Self-assessed against the repository's Guzzle-shaped test client: the focused tests execute the options path and verify both 529-to-ServerException and 400-to-ClientException translation. The repository does not install guzzlehttp/guzzle; live provider integration tests were not run because they make billable API calls and do not exercise this option bridge.

Decisions

The new option is scoped to buildGuzzleOptions(), so ordinary PSR-18 clients and ClientWithOptionsInterface implementations remain unchanged. No retries or dependency changes are introduced.

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[github-actions]

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.52%. Comparing base (a31b0ec) to head (bd6189d).

Additional details and impacted files

@@             Coverage Diff              @@
##              trunk     #266      +/-   ##
============================================
+ Coverage     86.49%   86.52%   +0.02%     
  Complexity     1327     1327              
============================================
  Files            68       68              
  Lines          4295     4297       +2     
============================================
+ Hits           3715     3718       +3     
+ Misses          580      579       -1     

Flag	Coverage Δ
unit	86.52% <100.00%> (+0.02%)	⬆️

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