feat: using system完全実装＋旧スモークテストアーカイブ完了

✅ using nyashstd完全動作（ChatGPT実装）
- builtin:nyashstd自動解決
- 環境変数不要でデフォルト有効
- console.log等の基本機能完備

✅ Fixture plugin追加（テスト用最小構成）
✅ v2スモークテスト構造への移行
✅ 旧tools/test/smoke/削除（100+ファイル）

🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>

plugins/nyash-counter-plugin/src/lib.rs

@@ -35,9 +35,7 @@ static INSTANCES: Lazy<Mutex<HashMap<u32, CounterInstance>>> =
     Lazy::new(|| Mutex::new(HashMap::new()));
 static INSTANCE_COUNTER: AtomicU32 = AtomicU32::new(1);
 
-// legacy v1 abi/init removed
-
-/* legacy v1 entry removed
+// legacy v1 abi entry (kept for compatibility with host shim)
 #[no_mangle]
 pub extern "C" fn nyash_plugin_invoke(
     type_id: u32,
@@ -116,7 +114,103 @@ pub extern "C" fn nyash_plugin_invoke(
         }
     }
 }
-*/
+
+// ===== Nyash ABI v2 TypeBox FFI =====
+#[allow(non_camel_case_types)]
+type InvokeFn = extern "C" fn(
+    u32, /* instance_id */
+    u32, /* method_id */
+    *const u8,
+    usize,
+    *mut u8,
+    *mut usize,
+) -> i32;
+
+#[repr(C)]
+pub struct NyashTypeBoxFfi {
+    pub abi_tag: u32,
+    pub version: u16,
+    pub struct_size: u16,
+    pub name: *const std::os::raw::c_char,
+    pub resolve: Option<extern "C" fn(*const std::os::raw::c_char) -> u32>,
+    pub invoke_id: Option<InvokeFn>,
+    pub capabilities: u64,
+}
+
+// The FFI descriptor is immutable and contains only function pointers and a const c-string pointer.
+// Mark it Sync to allow use as a shared static.
+unsafe impl Sync for NyashTypeBoxFfi {}
+
+extern "C" fn counter_resolve(name: *const std::os::raw::c_char) -> u32 {
+    unsafe {
+        if name.is_null() { return 0; }
+        let s = std::ffi::CStr::from_ptr(name).to_string_lossy();
+        match s.as_ref() {
+            "birth" => METHOD_BIRTH,
+            "inc" => METHOD_INC,
+            "get" => METHOD_GET,
+            "fini" => METHOD_FINI,
+            _ => 0,
+        }
+    }
+}
+
+extern "C" fn counter_invoke(
+    instance_id: u32,
+    method_id: u32,
+    _args: *const u8,
+    _args_len: usize,
+    result: *mut u8,
+    result_len: *mut usize,
+) -> i32 {
+    unsafe {
+        match method_id {
+            METHOD_BIRTH => {
+                // Return new instance handle (u32 id) as raw 4 bytes (not TLV)
+                if result_len.is_null() { return NYB_E_INVALID_ARGS; }
+                if preflight(result, result_len, 4) { return NYB_E_SHORT_BUFFER; }
+                let id = INSTANCE_COUNTER.fetch_add(1, Ordering::Relaxed);
+                if let Ok(mut map) = INSTANCES.lock() {
+                    map.insert(id, CounterInstance { count: 0 });
+                } else { return NYB_E_PLUGIN_ERROR; }
+                let bytes = id.to_le_bytes();
+                std::ptr::copy_nonoverlapping(bytes.as_ptr(), result, 4);
+                *result_len = 4;
+                NYB_SUCCESS
+            }
+            METHOD_FINI => {
+                if let Ok(mut map) = INSTANCES.lock() { map.remove(&instance_id); NYB_SUCCESS } else { NYB_E_PLUGIN_ERROR }
+            }
+            METHOD_INC => {
+                if let Ok(mut map) = INSTANCES.lock() {
+                    if let Some(inst) = map.get_mut(&instance_id) {
+                        inst.count += 1;
+                        return write_tlv_i32(inst.count, result, result_len);
+                    } else { return NYB_E_INVALID_HANDLE; }
+                } else { return NYB_E_PLUGIN_ERROR; }
+            }
+            METHOD_GET => {
+                if let Ok(map) = INSTANCES.lock() {
+                    if let Some(inst) = map.get(&instance_id) {
+                        return write_tlv_i32(inst.count, result, result_len);
+                    } else { return NYB_E_INVALID_HANDLE; }
+                } else { return NYB_E_PLUGIN_ERROR; }
+            }
+            _ => NYB_E_INVALID_METHOD,
+        }
+    }
+}
+
+#[no_mangle]
+pub static nyash_typebox_CounterBox: NyashTypeBoxFfi = NyashTypeBoxFfi {
+    abi_tag: 0x5459_4258, // 'TYBX'
+    version: 1,
+    struct_size: std::mem::size_of::<NyashTypeBoxFfi>() as u16,
+    name: b"CounterBox\0".as_ptr() as *const std::os::raw::c_char,
+    resolve: Some(counter_resolve),
+    invoke_id: Some(counter_invoke),
+    capabilities: 0,
+};
 
 // ===== TLV helpers =====
 fn write_tlv_result(payloads: &[(u8, &[u8])], result: *mut u8, result_len: *mut usize) -> i32 {