test: add 15 PHP security scanner fixtures

[WNZhao]

Summary

• add 15 inert PHP security-scanner fixtures under vulns/php/
• cover code/command/SQL injection, traversal, credentials, randomness, SSRF, unsafe deserialization, temp files, log injection, partial comparison, TLS bypass, redirect, type juggling, and XXE
• refresh generated vulnerability catalogs

Validation

• every .php file passes PHP 8.5 php -l
• all 15 files contain a SAFE: counterpart
• bash scripts/validate-test-case.sh (all 6 groups passed)
• git diff --check

All examples remain unreachable behind NEVER_RUN = false.

[WNZhao]

Settlement check for the completed fixture batches: PRs #201 through #213 are all merged and green, covering 195 security fixtures (15 per PR). The uGig task Q&A stated the rate was per file and that files could be stacked in one PR. INV-003 already covered the undisputed $3.25 partial payment; the remaining submitted amount is $48.75 ($22.50 for #201-#206 plus $26.25 for #207-#213). Please confirm acceptance, or identify any specific fixture that is rejected and the reason. After confirmation I will send one consolidated CoinPay invoice. Thank you.

[WNZhao]

Quick settlement follow-up: PROP-001 has been accepted and paid. PROP-002 remains at the discounted $10.75 settlement amount for PRs #207–#213. Please accept it today using the existing client response link so I can issue the invoice immediately: https://coinpayportal.com/proposals/respond/soyu_AYX5B3XbkKPOCgXD1mwrY2JwRQJaZ9LgVWZv0A