refactor(utils): 重构 FoodVectorTool 并优化 zero() 提示控制

- 重构 FoodVectorTool：移除单例 pageNum 状态污染问题，分页逻辑下沉为私有 fetchPage，saveFoodVector 改为私有，PAGE_SIZE 移入内部定义，对外统一暴露 loadAndSaveFoodVector 接口
- 更新 InitActivity、MainActivity 调用方，移除重复的 onPageFinish 回调
- SensorScaleUtils.zero() 新增 isShowToastRemind 可选参数，支持按需显示标定成功提示

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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

@@ -215,19 +215,16 @@ class MainActivity : BaseActivity<ActivityMainBinding>() {
                 lifecycleScope.launch {
                     withContext(Dispatchers.IO) {
                         FaceServer.getInstance().clearAllFaces()
-                    }
-                    withContext(Dispatchers.IO) {
                         ObjectBox.removeAll()
                     }
-                    FoodVectorTool.getFoodVector(
+                    FoodVectorTool.loadAndSaveFoodVector(
                         userViewModel = viewModel,
-                        onPageFinish = { list ->
-                            list?.let { FoodVectorTool.saveFoodVector(lifecycleScope,list) }
-                        },
+                        lifecycleScope = lifecycleScope,
                         successBlock = {
                             viewModel.getUserFaceCache(pageNo = 1)
-                        }, failureBlock = {
-                            hideWaitingDialog() // 显示提示信息
+                        },
+                        failureBlock = {
+                            hideWaitingDialog()
                             ToastUtils.showToast(it)
                         }
                     )