core(mir_call): implement Map.keys/values arrays via mem scan; smokes: add map_len_size/map_has; Stage‑B: bundle mix canary; CoreExecutor: add HAKO_CORE_DIRECT child path; docs: bundling order spec. Adjust map_len_size to avoid VM len() unsupported.

src/runner/core_executor.rs

@@ -13,8 +13,19 @@
  */
 
 use super::NyashRunner;
+use std::io::Write;
 
 pub(crate) fn run_json_v0(runner: &NyashRunner, json: &str) -> i32 {
+    // Optional: direct Core Dispatcher via child nyash (boxed)
+    // Toggle: HAKO_CORE_DIRECT=1 (alias: NYASH_CORE_DIRECT)
+    let core_direct = std::env::var("HAKO_CORE_DIRECT").ok().as_deref() == Some("1")
+        || std::env::var("NYASH_CORE_DIRECT").ok().as_deref() == Some("1");
+    if core_direct {
+        if let Some(rc) = try_run_core_direct(json) {
+            return rc;
+        }
+        eprintln!("[core-exec] direct Core failed; falling back to VM interpreter");
+    }
     let mut payload = json.to_string();
 
     let use_core_wrapper = crate::config::env::nyvm_core_wrapper();
@@ -63,3 +74,50 @@ pub(crate) fn run_json_v0(runner: &NyashRunner, json: &str) -> i32 {
     }
 }
 
+fn try_run_core_direct(json: &str) -> Option<i32> {
+    // Generate a temporary Hako program that includes the Core dispatcher
+    // and calls NyVmDispatcher.run(json), printing the numeric result.
+    let tmp_dir = std::path::Path::new("tmp");
+    let _ = std::fs::create_dir_all(tmp_dir);
+    let script_path = tmp_dir.join("core_exec_direct.hako");
+    // Escape JSON into Hako string literal (simple backslash+quote escaping)
+    let mut j = String::new();
+    for ch in json.chars() {
+        match ch {
+            '\\' => j.push_str("\\\\"),
+            '"' => j.push_str("\\\""),
+            _ => j.push(ch),
+        }
+    }
+    let code = format!(
+        "include \"lang/src/vm/core/dispatcher.hako\"\nstatic box Main {{ method main(args) {{ local j=\"{}\"; local r=NyVmDispatcher.run(j); print(r); return 0 }} }}\n",
+        j
+    );
+    if let Ok(mut f) = std::fs::File::create(&script_path) {
+        let _ = f.write_all(code.as_bytes());
+    } else {
+        return None;
+    }
+    // Determine nyash binary (current executable)
+    let exe = std::env::current_exe().ok()?;
+    let mut cmd = std::process::Command::new(exe);
+    crate::runner::child_env::apply_core_wrapper_env(&mut cmd);
+    // Quiet: parse only the last numeric line
+    let out = cmd
+        .args(["--backend", "vm", script_path.to_string_lossy().as_ref()])
+        .output()
+        .ok()?;
+    let stdout = String::from_utf8_lossy(&out.stdout);
+    // Parse last numeric line
+    let mut rc: Option<i32> = None;
+    for line in stdout.lines().rev() {
+        let s = line.trim();
+        if s.is_empty() { continue; }
+        if let Ok(v) = s.parse::<i64>() {
+            let m = ((v % 256) + 256) % 256;
+            rc = Some(m as i32);
+            break;
+        }
+    }
+    rc
+}