diff --git a/.github/audits/gh24280_ci_control.txt b/.github/audits/gh24280_ci_control.txt
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+++ b/.github/audits/gh24280_ci_control.txt
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+GH-24280 negative-control trigger (non-PHP, no runtime or build changes).
+The unchanged PHP-8.4 source at 6ec698758e50d0356a7befeca6b2bfaffffa15aa is tested.
+This inert file exists only to bypass the native Test workflow paths-ignore on *.md.
diff --git a/docs/audits/gh24280-php84-unmodified-control.md b/docs/audits/gh24280-php84-unmodified-control.md
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+# GH-24280 independent unmodified-base control
+
+This fork-only **DRAFT** intentionally changes no PHP source, Zend VM code, tests, or build configuration.
+
+- Exact parent: `PHP-8.4` SHA `6ec698758e50d0356a7befeca6b2bfaffffa15aa`
+- Candidate under test: [Xauele/php-src#2](https://github.com/Xauele/php-src/pull/2), SHA `7b5662a162b8ca9a18921cd119f28740a2c3017b`.
+- Candidate macOS Tracing JIT twice fails `ext/zip/tests/oo_torrentzip.phpt`, even though its patch changes only Zend foreach-by-reference and three PHPTs.
+- Candidate FreeBSD 13.5 fails package catalog bootstrap before compiling PHP: `pkgmir.geo.freebsd.org/FreeBSD:13:amd64/latest` is Not Found.
+
+This control makes GitHub Actions run the **existing unchanged repository CI matrix** against an unmodified PHP-8.4 tree. It will distinguish a pre-existing platform/environment failure from a patch-specific regression. Results are not predicted.
+
+**Acceptance policy:** the control and candidate must use equivalent jobs/toolchain. If the control reproduces the same failure, classify it as environmental/pre-existing and attach both logs; if the control passes, investigate the candidate, with **NO-GO** for upstream until resolved. This control PR is never intended to merge.