fix(main): 修复计算吃饭数量返回值小于1的问题

- 修改返回值逻辑，当计算结果小于1时返回1
- 防止吃饭数量为0或负值导致的异常情况
- 优化代码可读性，提升鲁棒性

app/src/main/java/com/sw/dualscreen/activity/MainActivity.kt

@@ -978,7 +978,7 @@ class MainActivity : BaseActivity<ActivityMainBinding>() {
         }
         val eatNum = (realWeight / specWeight).roundToInt()
         log("getEatNum:eatNum=$eatNum,realWeight=$realWeight,specWeight=$specWeight,realWeight/$specWeight=${realWeight / specWeight}}")
-        return eatNum;
+        return  if (eatNum < 1) 1 else eatNum;
     }
 
     /**