feat(fragment): 新增默认减重配置功能

- SpTool 新增 configWeight 属性，持久化存储默认减重克数
- 新增 WeightConfigFragment 及对应布局，支持数字输入和回填
- SingleFragmentActivity 注册 WEIGHT_CONFIG 页面类型
- SettingActivity 在食材采集下方新增减重配置入口
- PrepareFoodActivity 打开时从 SpTool.configWeight 初始化 initialWeight

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

app/src/main/java/com/shuwei/dish/match/model/SettingItem.kt

@@ -24,6 +24,8 @@ data class SettingItem(
         SEASONING_CONFIG,
         /** 食材采集 */
         FOOD_COLLECT,
+        /** 减重配置 */
+        WEIGHT_CONFIG,
         /** 数据库查看（隐藏项） */
         DB_INSPECT,
         /** 秤数据监控（隐藏项） */

app/src/main/java/com/shuwei/dish/match/ui/PrepareFoodActivity.kt

@@ -223,8 +223,8 @@ class PrepareFoodActivity : BaseActivity() {
     private var lastWeight = 0.0
     private var currentWeight = 0.0
 
-    /** 初始秤读数，净重 = 秤读数 - initialWeight */
+    /** 初始秤读数，净重 = 秤读数 - initialWeight，从 SpTool.configWeight 读取 */
-    private var initialWeight = 0.0
+    private var initialWeight = SpTool.configWeight.toDouble()
 
     /** 初始读数是否已从秤获取 */
 //    private var initialWeightReady = false

app/src/main/java/com/shuwei/dish/match/ui/SettingActivity.kt

@@ -99,6 +99,13 @@ class SettingActivity : BaseActivity() {
             title = "食材采集",
             onClick = { checkCameraPermission() }
         ),
+        SettingItem(
+            type = SettingItem.Type.WEIGHT_CONFIG,
+            title = "减重配置",
+            onClick = {
+                SingleFragmentActivity.start(this, SingleFragmentActivity.PageType.WEIGHT_CONFIG)
+            }
+        ),
         SettingItem(
             type = SettingItem.Type.DB_INSPECT,
             title = "数据库查看",

app/src/main/java/com/shuwei/dish/match/ui/SingleFragmentActivity.kt

@@ -9,6 +9,7 @@ import com.shuwei.dish.match.ui.fragment.DbInspectFragment
 import com.shuwei.dish.match.ui.fragment.VectorCollectionFragment
 import com.shuwei.dish.match.ui.fragment.DeviceConfigFragment
 import com.shuwei.dish.match.ui.fragment.SeasoningConfigFragment
+import com.shuwei.dish.match.ui.fragment.WeightConfigFragment
 import com.shuwei.dish.match.utils.ext.gone
 import com.shuwei.dish.match.utils.ext.visible
 
@@ -39,6 +40,9 @@ class SingleFragmentActivity : BaseActivity() {
 
         /** 数据库调试查看页 */
         DB_INSPECT,
+
+        /** 默认减重配置页 */
+        WEIGHT_CONFIG,
     }
 
     companion object {
@@ -101,6 +105,7 @@ class SingleFragmentActivity : BaseActivity() {
         PageType.COOK_MODE -> "菜品模式"
         PageType.SEASONING_CONFIG -> "调料区设置"
         PageType.DB_INSPECT -> "数据库查看"
+        PageType.WEIGHT_CONFIG -> "减重配置"
     }
 
     /**
@@ -111,6 +116,7 @@ class SingleFragmentActivity : BaseActivity() {
         PageType.COOK_MODE -> DeviceConfigFragment()
         PageType.SEASONING_CONFIG -> SeasoningConfigFragment()
         PageType.DB_INSPECT -> DbInspectFragment()
+        PageType.WEIGHT_CONFIG -> WeightConfigFragment()
     }
 
     override fun onResume() {

app/src/main/java/com/shuwei/dish/match/ui/fragment/WeightConfigFragment.kt

@@ -0,0 +1,46 @@
+package com.shuwei.dish.match.ui.fragment
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import com.shuwei.dish.match.base.BaseFragment
+import com.shuwei.dish.match.databinding.FragmentWeightConfigBinding
+import com.shuwei.dish.match.utils.SpTool
+import com.shuwei.dish.match.utils.ext.clickWithDebounce
+import com.shuwei.dish.match.utils.ext.toast
+
+/**
+ * 默认减重配置 Fragment
+ * 允许用户设置打开 PrepareFoodActivity 时的初始减重基准值（单位：克）
+ */
+class WeightConfigFragment : BaseFragment<FragmentWeightConfigBinding>() {
+
+    override fun inflateBinding(
+        inflater: LayoutInflater,
+        container: ViewGroup?
+    ): FragmentWeightConfigBinding {
+        return FragmentWeightConfigBinding.inflate(inflater, container, false)
+    }
+
+    override fun initialize() {
+        // 若已有配置值则回填到输入框
+        val saved = SpTool.configWeight
+        if (saved != 0) {
+            binding.etConfigWeight.setText(saved.toString())
+        }
+
+        binding.btnConfirm.clickWithDebounce {
+            val input = binding.etConfigWeight.text.toString().trim()
+            if (input.isEmpty()) {
+                toast("请输入减重值")
+                return@clickWithDebounce
+            }
+            val weight = input.toIntOrNull()
+            if (weight == null || weight < 0) {
+                toast("请输入有效的减重值")
+                return@clickWithDebounce
+            }
+            SpTool.configWeight = weight
+            toast("保存成功")
+        }
+    }
+}

app/src/main/java/com/shuwei/dish/match/utils/SpTool.kt

@@ -16,6 +16,8 @@ object SpTool {
     const val SCALE_DEVICE_PORT = "scaleDevicePort"
     /** 食堂 ID，默认 "0" */
     const val CANTEEN_ID = "canteenId"
+    /** 默认减重克数 */
+    const val CONFIG_WEIGHT = "configWeight"
 
     val pref = BaseApp.getSharedPref()!!
 
@@ -41,6 +43,13 @@ object SpTool {
             put(LAUNCH_PAGE_TYPE, value)
         }
 
+    /** 默认减重（克），打开 PrepareFoodActivity 时作为 initialWeight 基准值 */
+    var configWeight: Int
+        get() = getInt(CONFIG_WEIGHT, 0)
+        set(value) {
+            put(CONFIG_WEIGHT, value)
+        }
+
     /** 食堂 ID，持久化存储，默认 "0" */
     var canteenId: String
         get() = getString(CANTEEN_ID, "0")

app/src/main/res/layout/fragment_weight_config.xml

@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:background="@drawable/bg_other_page"
+    tools:ignore="HardcodedText">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="30dp"
+        android:layout_marginEnd="30dp"
+        android:background="@drawable/shape_white_30_corners"
+        android:orientation="vertical"
+        android:padding="30dp"
+        tools:ignore="UselessParent">
+
+        <FrameLayout
+            android:layout_width="match_parent"
+            android:layout_height="106dp"
+            android:background="@drawable/bg_bottom_line">
+
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_gravity="start|center_vertical"
+                android:text="默认减重配置"
+                android:textColor="@color/black"
+                android:textSize="28sp"
+                android:textStyle="bold" />
+        </FrameLayout>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="30dp"
+            android:gravity="center_vertical"
+            android:orientation="horizontal">
+
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="减重值（克）"
+                android:textColor="@color/black"
+                android:textSize="28sp" />
+
+            <EditText
+                android:id="@+id/etConfigWeight"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_marginStart="20dp"
+                android:layout_weight="1"
+                android:background="@drawable/shape_white_30_corners"
+                android:hint="请输入减重值"
+                android:inputType="number"
+                android:maxLength="6"
+                android:padding="16dp"
+                android:textColor="@color/black"
+                android:textColorHint="@color/gray_b4"
+                android:textSize="28sp" />
+        </LinearLayout>
+
+        <androidx.appcompat.widget.AppCompatButton
+            android:id="@+id/btnConfirm"
+            android:layout_width="match_parent"
+            android:layout_height="90dp"
+            android:layout_marginTop="40dp"
+            android:text="确认"
+            android:background="@drawable/shape_green_bg"
+            android:foreground="?android:attr/selectableItemBackground"
+            android:gravity="center"
+            android:textColor="@color/white"
+            android:textSize="32sp"
+            android:textStyle="bold" />
+
+    </LinearLayout>
+
+</FrameLayout>