Keep isolated document extraction working on macOS

docs/MACOS-RUNTIME.md

@@ -101,3 +101,16 @@ The broader workspace run exposes an existing stale permission-denial rollback
 expectation in `targeted_reconciliation` (current engine skips unreadable inputs).
 Strict current-toolchain Clippy also flags unchanged permission-literal and
 ANN-cache boolean expressions. These failures are not qualified as passing gates.
+
+### Native document extraction policy
+
+Mac parent/worker DOCX roundtrip and malformed-PDF rejection tests now pass.
+Darwin rejects finite `RLIMIT_AS` and `RLIMIT_DATA` on the tested system. The
+worker retains the30-second CPU limit; the parent checks resident memory through
+`proc_pidinfo` during its existing5ms polling loop and rejects usage above512MiB,
+killing/reaping its owned process group. Input/output bounds and the parent
+wall deadline remain active. This sampled RSS guard may overshoot between polls;
+it is not equivalent to a kernel-enforced hard address-space limit. Linux and
+Windows retain their existing resource policies. An owned live-child test
+verifies budget rejection; five process-owner tests and two actual parent/worker
+roundtrip/rejection tests pass on the Mac.