fix: Accept HTTP/1.1 responses in SocketPost to support proxies

[SNO7E-G]

Summary

Fixes false E_BAD_RESPONSE errors for users behind HTTP proxies or on hosting environments that rewrite outbound HTTP/1.0 traffic to HTTP/1.1.

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The Problem

SocketPost::submit() sends an HTTP/1.0 POST request to the reCAPTCHA API. When the response arrives, it checks the status line with a strict strpos() comparison:

if (0 !== strpos($response, 'HTTP/1.0 200 OK')) {
    // returns E_BAD_RESPONSE
}

Some proxies, reverse proxies, and hosting environments transparently upgrade the connection and respond with HTTP/1.1 200 OK. This causes a false-positive failure — the reCAPTCHA verification was actually successful, but the library rejects the response.

The Fix

Replace the rigid strpos() check with a regex that securely accepts both HTTP versions:

if (1 !== preg_match('#^HTTP/1\.[01] 200 OK#', $response)) {
    // returns E_BAD_RESPONSE
}

This regex:

• Anchors to the start of the response (^)
• Only matches HTTP/1.0 or HTTP/1.1 (no other versions like HTTP/2)
• Only matches status 200 OK (non-200 statuses are still correctly rejected)

Test Coverage

Added a new test testSubmitReturnsResponseWhenHttp11() that explicitly mocks an HTTP/1.1 200 OK response and asserts the body is returned correctly. The existing HTTP/1.0 tests remain unchanged and continue to pass.

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Verification

> vendor/bin/phpunit
OK (60 tests, 158 assertions)

> vendor/bin/phpstan
[OK] No errors

> vendor/bin/php-cs-fixer check
All 22 files are correct.

[coveralls]

coverage: 100.0%. remained the same
when pulling df61d9d on SNO7E-G:fix/socketpost-http11-proxy
into b6e64e7 on google:main.

[rowan-m]

Can you resolve the conflicts here as I had made some changes to the SocketPost class and test just before.

[SNO7E-G]

Can you resolve the conflicts here as I had made some changes to the SocketPost class and test just before.

Of course, no problem. I was waiting until you finished so I could pull all the changes along with the fixes.

#DONE