feat: Phase 2.4 NyRT→NyKernel Architecture Revolution 100%完了！

ChatGPT5 Pro設計分析による42%コード削減の完全実現：
- crates/nyrt → crates/nyash_kernel 完全移行
- with_legacy_vm_args系統11箇所削除（encode/birth/future/invoke系）
- Plugin-First Architecture統一（VM依存根絶）
- libnyash_kernel.a生成成功（0エラー・0警告）
- LLVM統合更新（build_llvm.sh, ny-llvmc対応）

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

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

crates/nyash_kernel/src/plugin/array.rs

@@ -0,0 +1,142 @@
+// ---- Array helpers for LLVM lowering (handle-based) ----
+// Exported as: nyash_array_get_h(i64 handle, i64 idx) -> i64
+#[no_mangle]
+pub extern "C" fn nyash_array_get_h(handle: i64, idx: i64) -> i64 {
+    use nyash_rust::{box_trait::IntegerBox, jit::rt::handles};
+    if std::env::var("NYASH_CLI_VERBOSE").ok().as_deref() == Some("1") {
+        eprintln!("[ARR] get_h(handle={}, idx={})", handle, idx);
+    }
+    if handle <= 0 || idx < 0 {
+        return 0;
+    }
+    if let Some(obj) = handles::get(handle) {
+        if let Some(arr) = obj
+            .as_any()
+            .downcast_ref::<nyash_rust::boxes::array::ArrayBox>()
+        {
+            let val = arr.get(Box::new(IntegerBox::new(idx)));
+            if let Some(ib) = val.as_any().downcast_ref::<IntegerBox>() {
+                if std::env::var("NYASH_CLI_VERBOSE").ok().as_deref() == Some("1") {
+                    eprintln!("[ARR] get_h => {}", ib.value);
+                }
+                return ib.value;
+            }
+        }
+    }
+    0
+}
+
+// Exported as: nyash_array_set_h(i64 handle, i64 idx, i64 val) -> i64
+#[no_mangle]
+pub extern "C" fn nyash_array_set_h(handle: i64, idx: i64, val: i64) -> i64 {
+    use nyash_rust::{box_trait::IntegerBox, jit::rt::handles};
+    if std::env::var("NYASH_CLI_VERBOSE").ok().as_deref() == Some("1") {
+        eprintln!("[ARR] set_h(handle={}, idx={}, val={})", handle, idx, val);
+    }
+    if handle <= 0 || idx < 0 {
+        return 0;
+    }
+    if let Some(obj) = handles::get(handle) {
+        if let Some(arr) = obj
+            .as_any()
+            .downcast_ref::<nyash_rust::boxes::array::ArrayBox>()
+        {
+            let i = idx as usize;
+            let len = arr.len();
+            if i < len {
+                let _ = arr.set(
+                    Box::new(IntegerBox::new(idx)),
+                    Box::new(IntegerBox::new(val)),
+                );
+            } else if i == len {
+                let _ = arr.push(Box::new(IntegerBox::new(val)));
+            } else {
+                // Do nothing for gaps (keep behavior conservative)
+            }
+            if std::env::var("NYASH_CLI_VERBOSE").ok().as_deref() == Some("1") {
+                eprintln!("[ARR] set_h done; size now {}", arr.len());
+            }
+            return 0;
+        }
+    }
+    0
+}
+
+// Exported as: nyash_array_push_h(i64 handle, i64 val) -> i64 (returns new length)
+#[no_mangle]
+pub extern "C" fn nyash_array_push_h(handle: i64, val: i64) -> i64 {
+    use nyash_rust::{
+        box_trait::{IntegerBox, NyashBox},
+        jit::rt::handles,
+    };
+    if std::env::var("NYASH_CLI_VERBOSE").ok().as_deref() == Some("1") {
+        eprintln!("[ARR] push_h(handle={}, val={})", handle, val);
+    }
+    if handle <= 0 {
+        return 0;
+    }
+    if let Some(obj) = handles::get(handle) {
+        if let Some(arr) = obj
+            .as_any()
+            .downcast_ref::<nyash_rust::boxes::array::ArrayBox>()
+        {
+            // If val is handle, try to use it; otherwise treat as integer
+            let vbox: Box<dyn NyashBox> = if val > 0 {
+                if let Some(o) = handles::get(val) {
+                    o.clone_box()
+                } else {
+                    Box::new(IntegerBox::new(val))
+                }
+            } else {
+                Box::new(IntegerBox::new(val))
+            };
+            let _ = arr.push(vbox);
+            let len = arr.len() as i64;
+            if std::env::var("NYASH_CLI_VERBOSE").ok().as_deref() == Some("1") {
+                eprintln!("[ARR] push_h -> len {}", len);
+            }
+            return len;
+        }
+    }
+    0
+}
+
+// Exported as: nyash_array_length_h(i64 handle) -> i64
+#[no_mangle]
+pub extern "C" fn nyash_array_length_h(handle: i64) -> i64 {
+    use nyash_rust::jit::rt::handles;
+    if handle <= 0 {
+        return 0;
+    }
+    if let Some(obj) = handles::get(handle) {
+        if let Some(arr) = obj
+            .as_any()
+            .downcast_ref::<nyash_rust::boxes::array::ArrayBox>()
+        {
+            return arr.len() as i64;
+        }
+    }
+    0
+}
+
+// --- AOT ObjectModule dotted-name aliases (Array) ---
+// Provide dotted symbol names expected by ObjectBuilder lowering, forwarding to existing underscored exports.
+#[export_name = "nyash.array.get_h"]
+pub extern "C" fn nyash_array_get_h_alias(handle: i64, idx: i64) -> i64 {
+    nyash_array_get_h(handle, idx)
+}
+
+#[export_name = "nyash.array.set_h"]
+pub extern "C" fn nyash_array_set_h_alias(handle: i64, idx: i64, val: i64) -> i64 {
+    nyash_array_set_h(handle, idx, val)
+}
+
+#[export_name = "nyash.array.push_h"]
+pub extern "C" fn nyash_array_push_h_alias(handle: i64, val: i64) -> i64 {
+    nyash_array_push_h(handle, val)
+}
+
+#[export_name = "nyash.array.len_h"]
+pub extern "C" fn nyash_array_len_h_alias(handle: i64) -> i64 {
+    nyash_array_length_h(handle)
+}