feat: Prepare for code modularization and cleanup

- Archive old documentation and test files to `docs/archive/` and `local_tests/`.
- Remove various temporary and old files from the project root.
- Add `nekocode-rust` analysis tool and its output files (`nekocode/`, `.nekocode_sessions/`, `analysis.json`).
- Minor updates to `apps/chip8_nyash/chip8_emulator.nyash` and `local_tests` files.

This commit cleans up the repository and sets the stage for further code modularization efforts, particularly in the `src/interpreter` and `src/parser` modules, based on recent analysis.

local_tests/test_array_debug.nyash

@@ -0,0 +1,31 @@
+// ArrayBox動作確認テスト
+static box ArrayTest {
+    init { arr, random }
+    
+    main() {
+        me.random = new RandomBox()
+        me.arr = new ArrayBox()
+        
+        print("=== ArrayBox動作テスト ===")
+        
+        // 初期状態確認
+        print("初期長さ: " + me.arr.length().toString())
+        
+        // 要素追加
+        me.arr.push("要素1")
+        print("push後の長さ: " + me.arr.length().toString())
+        
+        me.arr.push("要素2")
+        print("2回目push後の長さ: " + me.arr.length().toString())
+        
+        // 乱数テスト
+        local randomNum
+        randomNum = me.random.next()
+        print("乱数生成: " + randomNum.toString())
+        
+        // ArrayBox内容確認
+        print("配列内容: " + me.arr.toString())
+        
+        return "テスト完了"
+    }
+}