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_user_defined_box.nyash

@@ -0,0 +1,14 @@
+box DataBox {
+    init { value }
+    
+    pack(v) {
+        me.value = v
+    }
+}
+
+static box Main {
+    main() {
+        local obj = new DataBox(42)
+        return obj.value
+    }
+}