Refine normalized bridge direct path and env guard

src/mir/join_ir/normalized/shape_guard.rs

@@ -10,6 +10,11 @@ pub(crate) enum NormalizedDevShape {
     JsonparserAtoiMini,
 }
 
+/// 直接 Normalized→MIR ブリッジで扱う shape を返す（dev 限定）。
+pub(crate) fn direct_shapes(module: &JoinModule) -> Vec<NormalizedDevShape> {
+    supported_shapes(module)
+}
+
 pub(crate) fn supported_shapes(module: &JoinModule) -> Vec<NormalizedDevShape> {
     let mut shapes = Vec::new();
     if is_jsonparser_atoi_mini(module) {
@@ -27,6 +32,11 @@ pub(crate) fn supported_shapes(module: &JoinModule) -> Vec<NormalizedDevShape> {
     shapes
 }
 
+#[allow(dead_code)]
+pub(crate) fn is_direct_supported(module: &JoinModule) -> bool {
+    !direct_shapes(module).is_empty()
+}
+
 pub(crate) fn is_pattern1_mini(module: &JoinModule) -> bool {
     module.is_structured() && find_loop_step(module).is_some()
 }