Phase 10.10: GC Switchable Runtime & Unified Debug System 実装完了

Phase 10.10の主要実装:
- GcConfigBox: GC設定の実行時制御（counting/trace/barrier_strict）
- DebugConfigBox: デバッグ設定の統一管理（JIT events/stats/dump/dot）
- メソッドディスパッチ: system_methods.rsで両Boxのメソッド実装
- CountingGC動作確認: write_barriers正常カウント（VM実行時）

技術的詳細:
- BoxCore/BoxBase統一アーキテクチャを活用
- setFlag/getFlag/apply/summaryメソッドで統一API提供
- 環境変数経由でVM/JITランタイムと連携
- GcConfigBox.apply()は次回実行から有効（ランタイム作成前に環境変数参照）

テスト済み:
- examples/gc_counting_demo.nyash: CountingGCの動作確認
- write_barriers=3でArray.push/set, Map.setを正しくカウント
- NYASH_GC_TRACE=1でGC統計出力確認

Box-First哲学の体現: 設定も制御も観測もすべてBox！

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

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

src/runner.rs

@@ -77,6 +77,10 @@ impl NyashRunner {
             jc.handle_debug |= self.config.jit_handle_debug;
             jc.native_f64 |= self.config.jit_native_f64;
             jc.native_bool |= self.config.jit_native_bool;
+            // If events are enabled and no threshold is provided, force threshold=1 so lowering runs and emits events
+            if std::env::var("NYASH_JIT_EVENTS").ok().as_deref() == Some("1") && jc.threshold.is_none() {
+                jc.threshold = Some(1);
+            }
             if self.config.jit_only { std::env::set_var("NYASH_JIT_ONLY", "1"); }
             // Apply runtime capability probe (e.g., disable b1 ABI if unsupported)
             let caps = nyash_rust::jit::config::probe_capabilities();
@@ -321,7 +325,42 @@ impl NyashRunner {
         match vm.execute_module(&compile_result.module) {
             Ok(result) => {
                 println!("✅ VM execution completed successfully!");
-                println!("Result: {:?}", result);
+                if let Some(func) = compile_result.module.functions.get("main") {
+                    use nyash_rust::mir::MirType;
+                    use nyash_rust::box_trait::{NyashBox, IntegerBox, BoolBox, StringBox};
+                    use nyash_rust::boxes::FloatBox;
+                    let (ety, sval) = match &func.signature.return_type {
+                        MirType::Float => {
+                            if let Some(fb) = result.as_any().downcast_ref::<FloatBox>() {
+                                ("Float", format!("{}", fb.value))
+                            } else if let Some(ib) = result.as_any().downcast_ref::<IntegerBox>() {
+                                ("Float", format!("{}", ib.value as f64))
+                            } else { ("Float", result.to_string_box().value) }
+                        }
+                        MirType::Integer => {
+                            if let Some(ib) = result.as_any().downcast_ref::<IntegerBox>() {
+                                ("Integer", ib.value.to_string())
+                            } else { ("Integer", result.to_string_box().value) }
+                        }
+                        MirType::Bool => {
+                            if let Some(bb) = result.as_any().downcast_ref::<BoolBox>() {
+                                ("Bool", bb.value.to_string())
+                            } else if let Some(ib) = result.as_any().downcast_ref::<IntegerBox>() {
+                                ("Bool", (ib.value != 0).to_string())
+                            } else { ("Bool", result.to_string_box().value) }
+                        }
+                        MirType::String => {
+                            if let Some(sb) = result.as_any().downcast_ref::<StringBox>() {
+                                ("String", sb.value.clone())
+                            } else { ("String", result.to_string_box().value) }
+                        }
+                        _ => { (result.type_name(), result.to_string_box().value) }
+                    };
+                    println!("ResultType(MIR): {}", ety);
+                    println!("Result: {}", sval);
+                } else {
+                    println!("Result: {:?}", result);
+                }
             },
             Err(e) => {
                 eprintln!("❌ VM execution error: {}", e);