SNAKE game v0.3: round screen, swipe control

- 16x16 grid, 320px board centered on round 466 screen, designWidth 466
- pure snake logic in src/common/snake.js (step/turn/rotateDir/spawnFood, TDD'd)
- for-directive segment rendering, show-gated game-over overlay, 300ms tick
- swipe direction input (crown rotation confirmed unsupported on Vela S4)
- tests: snake logic + page wiring

package.json

@@ -0,0 +1,15 @@
+{
+  "name": "xiaomi-vela-s4-hello-world",
+  "version": "1.0.0",
+  "private": true,
+  "description": "Minimal Xiaomi Vela JS Hello World app for Xiaomi Watch S4",
+  "scripts": {
+    "build": "aiot build",
+    "release": "aiot release",
+    "build:source-map": "aiot build --devtool=source-map",
+    "help": "aiot build -h"
+  },
+  "devDependencies": {
+    "aiot-toolkit": "2.0.5"
+  }
+}