vm(hako): add v1 reader/dispatcher (flagged), commonize mir_call handler, share block scan; smokes: add v1 hakovm canary; docs: 20.37/20.38 plans, OOB policy; runner: v1 hakovm toggle; include SKIP summary

src/runner/dispatch.rs

@@ -42,6 +42,47 @@ pub(crate) fn execute_file_with_backend(runner: &NyashRunner, filename: &str) {
 
     // Direct v0 bridge when requested via CLI/env
     let groups = runner.config.as_groups();
+    // Diagnostic/Exec: accept MIR JSON file direct (experimental; default OFF)
+    if let Some(path) = groups.parser.mir_json_file.as_ref() {
+        match std::fs::read_to_string(path) {
+            Ok(text) => {
+                // Try schema v1 first (preferred by emitter)
+                match crate::runner::json_v1_bridge::try_parse_v1_to_module(&text) {
+                    Ok(Some(module)) => {
+                        crate::cli_v!("[mir-json] schema=v1 executing {} (len={})", path, text.len());
+                        let rc = runner.execute_mir_module_quiet_exit(&module);
+                        std::process::exit(rc);
+                    }
+                    Ok(None) => {
+                        // Not v1 schema; attempt minimal v0 loader
+                        if text.contains("\"functions\"") && text.contains("\"blocks\"") {
+                            match crate::runner::mir_json_v0::parse_mir_v0_to_module(&text) {
+                                Ok(module) => {
+                                    crate::cli_v!("[mir-json] schema=v0 executing {} (len={})", path, text.len());
+                                    let rc = runner.execute_mir_module_quiet_exit(&module);
+                                    std::process::exit(rc);
+                                }
+                                Err(e) => {
+                                    eprintln!("❌ MIR JSON v0 parse error: {}", e);
+                                    std::process::exit(1);
+                                }
+                            }
+                        }
+                        eprintln!("❌ MIR JSON invalid or unsupported shape: {}", path);
+                        std::process::exit(1);
+                    }
+                    Err(e) => {
+                        eprintln!("❌ MIR JSON parse error (v1): {}", e);
+                        std::process::exit(1);
+                    }
+                }
+            }
+            Err(e) => {
+                eprintln!("❌ Error reading MIR JSON {}: {}", path, e);
+                std::process::exit(1);
+            }
+        }
+    }
     let use_ny_parser = groups.parser.parser_ny
         || std::env::var("NYASH_USE_NY_PARSER").ok().as_deref() == Some("1");
     if use_ny_parser {
@@ -236,10 +277,13 @@ impl NyashRunner {
                     if let Some(_sb) = result.as_any().downcast_ref::<StringBox>() {
                         return 0; // strings do not define rc semantics yet
                     }
-                    0
-                } else {
-                    0
                 }
+                // Global fallbacks when signature is missing or imprecise
+                if let Some(ib) = result.as_any().downcast_ref::<IntegerBox>() { return to_rc(ib.value); }
+                if let Some(bb) = result.as_any().downcast_ref::<BoolBox>() { return if bb.value { 1 } else { 0 }; }
+                if let Some(fb) = result.as_any().downcast_ref::<FloatBox>() { return to_rc(fb.value as i64); }
+                if let Some(_sb) = result.as_any().downcast_ref::<StringBox>() { return 0; }
+                0
             }
             Err(_) => 1,
         }