feat: add Japanese localization for smalrubot S1 sensor labels

- Add sensorPositionsMenu namespace translations with port numbers:
  - 左(A4), 右(A5), タッチ(A2), 光(A6), 音(A7)
- Simplify positionsMenu for motors/LEDs to just '左', '右'
- Improves hardware port visibility and user experience
- Supports unified sensor label namespace from scratch-vm

Related to: #405
Companion to: smalruby/scratch-vm#37

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

Co-Authored-By: Claude <[email protected]>

Author: takaokouji

src/locales/ja.js

@@ -49,11 +49,13 @@ export default {
     'smalrubotS1.actionMenu.turnLeft': '左に曲げる',
     'smalrubotS1.actionMenu.turnRight': '右に曲げる',
     'smalrubotS1.actionMenu.stop': '止める',
-    'smalrubotS1.positionsMenu.left': '左 (A4)',
-    'smalrubotS1.positionsMenu.right': '右 (A5)',
-    'smalrubotS1.positionsMenu.touch': 'タッチ (A2)',
-    'smalrubotS1.positionsMenu.light': '光 (A6)',
-    'smalrubotS1.positionsMenu.sound': '音 (A7)',
+    'smalrubotS1.positionsMenu.left': '左',
+    'smalrubotS1.positionsMenu.right': '右',
+    'smalrubotS1.sensorPositionsMenu.left': '左(A4)',
+    'smalrubotS1.sensorPositionsMenu.right': '右(A5)',
+    'smalrubotS1.sensorPositionsMenu.touch': 'タッチ(A2)',
+    'smalrubotS1.sensorPositionsMenu.light': '光(A6)',
+    'smalrubotS1.sensorPositionsMenu.sound': '音(A7)',
     'gui.smalruby3.blockDisplayModal.title': 'ブロック表示設定',
     'gui.smalruby3.blockDisplayModal.selectAll': 'すべて選択',
     'gui.smalruby3.blockDisplayModal.selectNone': 'すべて選択解除',