runner: introduce CoreExecutor box for JSON→exec; wire Gate‑C pipe to CoreExecutor. Stage‑B bundling: duplicate name Fail‑Fast + mix canary; add Core Map/String positive smokes; add Gate‑C budget opt‑in canary; docs: Exit Code Policy; apply child_env in PyVM common util.

src/runner/modes/common_util/pyvm.rs

@@ -35,6 +35,7 @@ pub fn run_pyvm_harness(module: &crate::mir::MirModule, tag: &str) -> Result<i32
     };
     // Optional: Mini‑VM stdin loader — when enabled, read entire stdin and pass as argv[0]
     let mut cmd = std::process::Command::new(py3);
+    crate::runner::child_env::apply_core_wrapper_env(&mut cmd);
     if std::env::var("NYASH_MINIVM_READ_STDIN").ok().as_deref() == Some("1") {
         use std::io::Read;
         let mut buf = String::new();
@@ -95,6 +96,7 @@ pub fn run_pyvm_harness_lib(module: &nyash_rust::mir::MirModule, tag: &str) -> R
         "Main.main"
     };
     let mut cmd = std::process::Command::new(py3);
+    crate::runner::child_env::apply_core_wrapper_env(&mut cmd);
     if std::env::var("NYASH_MINIVM_READ_STDIN").ok().as_deref() == Some("1") {
         use std::io::Read;
         let mut buf = String::new();