fix(mir): PHI検証panic修正 - update_cfg()を検証前に呼び出し

A案実装: debug_verify_phi_inputs呼び出し前にCFG predecessorを更新

修正箇所（7箇所）:
- src/mir/builder/phi.rs:50, 73, 132, 143
- src/mir/builder/ops.rs:273, 328, 351

根本原因:
- Branch/Jump命令でsuccessorは即座に更新
- predecessorはupdate_cfg()で遅延再構築
- PHI検証が先に実行されてpredecessor未更新でpanic

解決策:
- 各debug_verify_phi_inputs呼び出し前に
  if let Some(func) = self.current_function.as_mut() {
      func.update_cfg();
  }
  を挿入してCFGを同期

影響: if/else文、論理演算子(&&/||)のPHI生成が正常動作

src/runner/pipeline.rs

@@ -206,18 +206,21 @@ pub(super) fn resolve_using_target(
                 // Compute entry: main or <dir_last>.nyash
                 let base = std::path::Path::new(&pkg.path);
                 let out = if let Some(m) = &pkg.main {
-                    if base.extension().and_then(|s| s.to_str()) == Some("nyash") {
+                    if matches!(base.extension().and_then(|s| s.to_str()), Some("nyash") | Some("hako")) {
                         // path is a file; ignore main and use as-is
                         pkg.path.clone()
                     } else {
                         base.join(m).to_string_lossy().to_string()
                     }
                 } else {
-                    if base.extension().and_then(|s| s.to_str()) == Some("nyash") {
+                    if matches!(base.extension().and_then(|s| s.to_str()), Some("nyash") | Some("hako")) {
                         pkg.path.clone()
                     } else {
                         let leaf = base.file_name().and_then(|s| s.to_str()).unwrap_or(tgt);
-                        base.join(format!("{}.nyash", leaf)).to_string_lossy().to_string()
+                        // prefer .hako when package path points to a directory without explicit main
+                        let hako = base.join(format!("{}.hako", leaf));
+                        if hako.exists() { hako.to_string_lossy().to_string() }
+                        else { base.join(format!("{}.nyash", leaf)).to_string_lossy().to_string() }
                     }
                 };
                 if trace {