Complete Phase 5.1: Add terminator handling for nested control flow

Co-authored-by: moe-charm <217100418+moe-charm@users.noreply.github.com>

test_box_creation.nyash

@@ -1,35 +0,0 @@
-// 🧪 新Box作成テスト - メソッド呼び出しなし
-
-print("=== New Box Creation Test ===")
-
-// 📊 BufferBox Test
-print("🔹 Creating BufferBox...")
-local buffer
-buffer = new BufferBox()
-print("✅ BufferBox created successfully!")
-
-// 🔍 RegexBox Test  
-print("🔹 Creating RegexBox...")
-local regex
-regex = new RegexBox("[0-9]+")
-print("✅ RegexBox created successfully!")
-
-// 📋 JSONBox Test
-print("🔹 Creating JSONBox...")
-local json
-json = new JSONBox("{\"name\": \"test\"}")
-print("✅ JSONBox created successfully!")
-
-// 🌊 StreamBox Test
-print("🔹 Creating StreamBox...")
-local stream
-stream = new StreamBox()
-print("✅ StreamBox created successfully!")
-
-// 🌐 HTTPClientBox Test
-print("🔹 Creating HTTPClientBox...")
-local http
-http = new HTTPClientBox()
-print("✅ HTTPClientBox created successfully!")
-
-print("\n🎉 All Arc<Mutex> Boxes created successfully!")