runner: add NyVM wrapper core_bridge (canonicalize/dump) + opt-in wrapper canary; export module in common_util

lang/src/compiler/entry/compiler.hako

@@ -27,6 +27,7 @@ static box Main {
   }
 
   _collect_flags(args) {
+    // Stage-A flags: emit/source/return only
     local flags = { emit: 0, ret: null, source: null }
     if args == null { return flags }
 
@@ -210,17 +211,17 @@ static box Main {
     // expr like: {"a":1,"b":2} - Stage‑A: minimal implementation for basic key/value pairs
     local inner = me._trim(expr.substring(1, expr.length()-1))
     if inner == "" { return me._emit_call("map.of", "") }
-    
+
     local out = ""
     local i = 0
     local n = inner.length()
     loop(i <= n) {
       // find next comma or end
       local j = i
-      loop(j < n) { 
-        local ch = inner.substring(j,j+1) 
-        if ch == "," { break } 
-        j = j + 1 
+      loop(j < n) {
+        local ch = inner.substring(j,j+1)
+        if ch == "," { break }
+        j = j + 1
       }
       local jj = j
       if jj >= n { jj = n }
@@ -466,7 +467,7 @@ static box Main {
     if flags.emit == 1 {
       local json = me._compile_source_to_json_v0(flags.source)
       print(json)
-      return
+      return 0
     }
     // Stage-A は --min-json 指定時のみ JSON を出力
     if flags.source != null && flags.source != "" {

lang/src/compiler/entry/compiler_stageb.hako

@@ -0,0 +1,74 @@
+// Stage-B compiler entry — ParserBox → FlowEntry emit-only
+
+using "lang/src/compiler/parser/parser_box.hako" as ParserBox
+using "lang/src/compiler/pipeline_v2/flow_entry.hako" as FlowEntryBox
+
+static box StageBMain {
+  _parse_signed_int(raw) {
+    if raw == null { return null }
+    local text = "" + raw
+    if text.length() == 0 { return null }
+    local sign = 1
+    local idx = 0
+    if text.length() > 0 && text.substring(0, 1) == "-" {
+      sign = -1
+      idx = 1
+    }
+    if idx >= text.length() { return null }
+    local acc = 0
+    loop(idx < text.length()) {
+      local ch = text.substring(idx, idx + 1)
+      if ch < "0" || ch > "9" { return null }
+      local digit = "0123456789".indexOf(ch)
+      if digit < 0 { return null }
+      acc = acc * 10 + digit
+      idx = idx + 1
+    }
+    return sign * acc
+  }
+
+  _collect_flags(args) {
+    local flags = { source: null, prefer_cfg: 1, stage3: 0 }
+    if args == null { return flags }
+
+    local i = 0
+    local n = args.length()
+    loop(i < n) {
+      local token = "" + args.get(i)
+      if token == "--source" && i + 1 < n {
+        flags.source = "" + args.get(i + 1)
+        i = i + 1
+      } else if token == "--prefer-cfg" && i + 1 < n {
+        local parsed = me._parse_signed_int(args.get(i + 1))
+        if parsed != null { flags.prefer_cfg = parsed }
+        i = i + 1
+      } else if token == "--stage3" {
+        flags.stage3 = 1
+      }
+      i = i + 1
+    }
+    return flags
+  }
+
+  main(args) {
+    local flags = me._collect_flags(args)
+    local src = flags.source
+    if src == null || src == "" {
+      print("{\"version\":0,\"kind\":\"Program\",\"body\":[{\"type\":\"Return\",\"expr\":{\"type\":\"Int\",\"value\":0}}]}")
+      return 0
+    }
+    local p = new ParserBox()
+    if flags.stage3 == 1 { p.stage3_enable(1) }
+    p.extract_usings(src)
+    local usings_json = p.get_usings_json()
+    p.extract_externs(src)
+    local externs_json = p.get_externs_json()
+    local ast_json = p.parse_program2(src)
+    local prefer = flags.prefer_cfg
+    local jv0 = FlowEntryBox.emit_v0_from_ast(ast_json, prefer)
+    // Attach usings metadata when available（Stage-B pipeline consumes via resolver）
+    if jv0 == null || jv0 == "" { jv0 = "{\"version\":0,\"kind\":\"Program\",\"body\":[{\"type\":\"Return\",\"expr\":{\"type\":\"Int\",\"value\":0}}]}" }
+    print(jv0)
+    return 0
+  }
+}