feat(phase94): Box→Service conversion with actual registry integration

Phase 94完全達成 - UnifiedBoxRegistryから実際のBoxを取得してServiceに変換

### 実装成果
- ✅ 6個のAdapter実装（StringBox/Integer/Bool/Array/Map/Console）
- ✅ Dummy実装完全削除（38行削減）
- ✅ Fail-Fast原則徹底（フォールバック削除）
- ✅ テスト7/7 PASS（100%）

### 変更ファイル
- src/runtime/core_services.rs: 6個のAdapter実装（+93行）
- src/runtime/plugin_host.rs: 実際のBox取得ロジック（+54行）、Dummy削除（-17行）
- src/runtime/mod.rs: フォールバック削除（-8行）

### 技術的成果
- Box<dyn NyashBox>を直接保持（型安全性確保）
- registry.create_box()で実際のBoxインスタンス取得
- BuiltinBoxFactory登録でcore_required Boxes提供

### 次のステップ
Phase 95: Service traitメソッド実装（Console/String/Array/Map）

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/runtime/core_services.rs

@@ -5,6 +5,7 @@
 
 use std::sync::Arc;
 use crate::runtime::CoreBoxId;
+use crate::box_trait::NyashBox;
 
 /// StringBox Service trait
 pub trait StringService: Send + Sync {
@@ -80,20 +81,108 @@ impl CoreServices {
         // Phase 92 以降で各 Service の初期化を検証
     }
 
-    /// Phase 93: ダミー実装（Phase 94 で削除予定）
-    pub fn dummy() -> Self {
-        use crate::runtime::plugin_host::*;
-        Self {
-            string: Arc::new(DummyStringService),
-            integer: Arc::new(DummyIntegerService),
-            bool: Arc::new(DummyBoolService),
-            array: Arc::new(DummyArrayService),
-            map: Arc::new(DummyMapService),
-            console: Arc::new(DummyConsoleService),
-        }
+}
+
+// ============================================================================
+// Phase 94: Adapter Pattern - Box → Service 変換
+// ============================================================================
+
+/// StringBox → StringService Adapter
+pub struct StringBoxAdapter {
+    #[allow(dead_code)]
+    inner: Box<dyn NyashBox>,
+}
+
+impl StringBoxAdapter {
+    pub fn new(box_instance: Box<dyn NyashBox>) -> Self {
+        Self { inner: box_instance }
     }
 }
 
+impl StringService for StringBoxAdapter {
+    // Phase 95 以降で実装
+}
+
+/// IntegerBox → IntegerService Adapter
+pub struct IntegerBoxAdapter {
+    #[allow(dead_code)]
+    inner: Box<dyn NyashBox>,
+}
+
+impl IntegerBoxAdapter {
+    pub fn new(box_instance: Box<dyn NyashBox>) -> Self {
+        Self { inner: box_instance }
+    }
+}
+
+impl IntegerService for IntegerBoxAdapter {
+    // Phase 95 以降で実装
+}
+
+/// BoolBox → BoolService Adapter
+pub struct BoolBoxAdapter {
+    #[allow(dead_code)]
+    inner: Box<dyn NyashBox>,
+}
+
+impl BoolBoxAdapter {
+    pub fn new(box_instance: Box<dyn NyashBox>) -> Self {
+        Self { inner: box_instance }
+    }
+}
+
+impl BoolService for BoolBoxAdapter {
+    // Phase 95 以降で実装
+}
+
+/// ArrayBox → ArrayService Adapter
+pub struct ArrayBoxAdapter {
+    #[allow(dead_code)]
+    inner: Box<dyn NyashBox>,
+}
+
+impl ArrayBoxAdapter {
+    pub fn new(box_instance: Box<dyn NyashBox>) -> Self {
+        Self { inner: box_instance }
+    }
+}
+
+impl ArrayService for ArrayBoxAdapter {
+    // Phase 95 以降で実装
+}
+
+/// MapBox → MapService Adapter
+pub struct MapBoxAdapter {
+    #[allow(dead_code)]
+    inner: Box<dyn NyashBox>,
+}
+
+impl MapBoxAdapter {
+    pub fn new(box_instance: Box<dyn NyashBox>) -> Self {
+        Self { inner: box_instance }
+    }
+}
+
+impl MapService for MapBoxAdapter {
+    // Phase 95 以降で実装
+}
+
+/// ConsoleBox → ConsoleService Adapter
+pub struct ConsoleBoxAdapter {
+    #[allow(dead_code)]
+    inner: Box<dyn NyashBox>,
+}
+
+impl ConsoleBoxAdapter {
+    pub fn new(box_instance: Box<dyn NyashBox>) -> Self {
+        Self { inner: box_instance }
+    }
+}
+
+impl ConsoleService for ConsoleBoxAdapter {
+    // Phase 95 以降で実装
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;