test: add 15 Objective-C security scanner fixtures

[WNZhao]

Summary

• add 15 inert Objective-C security-scanner fixtures under vulns/objective-c/
• cover command/SQL injection, traversal, credentials, randomness, SSRF, memory safety, integer overflow, partial comparison, temp files, format strings, TLS bypass, redirects, and diagnostic exposure
• refresh generated vulnerability catalogs

Validation

• every .m file passes clang -fsyntax-only -x objective-c -std=c11 -Wall -Wextra -Werror
• bash scripts/validate-test-case.sh (all 6 groups passed)
• git diff --check

All examples remain unreachable behind NEVER_RUN = 0.