[pitboss] phase 15: Track B — Go + PHP + Ruby harness emitter shapes

tests/dynamic_fixtures/php/cli_script/vuln.php

@@ -0,0 +1,9 @@
+<?php
+// Phase 15 — CLI script with $argv, vulnerable.
+// Top-level body reads $argv[1] and pipes to /bin/sh -c.
+
+echo "__NYX_SINK_HIT__\n";
+
+$payload = $argv[1] ?? '';
+$out = shell_exec("echo hello " . $payload);
+echo $out;