Add custom main tab bar with global scan-to-verify flow.

Introduce configurable custom TabBar with order badge, central scanner routing to verification orders, and update the migration checklist for recently completed modules.

Co-authored-by: Cursor <cursoragent@cursor.com>

suixinkan/Features/Main/Views/CustomMainTabBar.swift

@@ -0,0 +1,155 @@
+//
+//  CustomMainTabBar.swift
+//  suixinkan
+//
+//  Created by Codex on 2026/6/23.
+//
+
+import SwiftUI
+
+/// 自定义主 TabBar，展示四个一级入口和中间扫码核销按钮。
+struct CustomMainTabBar: View {
+    @Binding var selectedTab: AppTab
+
+    let orderBadgeText: String?
+    let onScanTap: () -> Void
+
+    private let items = CustomMainTabItem.defaultItems
+
+    var body: some View {
+        HStack(alignment: .center, spacing: 0) {
+            CustomMainTabBarItem(
+                item: items[0],
+                selectedTab: $selectedTab,
+                badgeText: nil
+            )
+            CustomMainTabBarItem(
+                item: items[1],
+                selectedTab: $selectedTab,
+                badgeText: orderBadgeText
+            )
+            CustomMainTabBarCenterAction(onScanTap: onScanTap)
+                .frame(width: 74)
+            CustomMainTabBarItem(
+                item: items[2],
+                selectedTab: $selectedTab,
+                badgeText: nil
+            )
+            CustomMainTabBarItem(
+                item: items[3],
+                selectedTab: $selectedTab,
+                badgeText: nil
+            )
+        }
+        .frame(maxWidth: .infinity)
+        .frame(height: 72)
+        .padding(.horizontal, 22)
+        .background(.white)
+        .overlay(alignment: .top) {
+            Rectangle()
+                .fill(Color.black.opacity(0.04))
+                .frame(height: 0.5)
+        }
+    }
+}
+
+/// 自定义 TabBar 单个入口的静态配置。
+private struct CustomMainTabItem {
+    let tab: AppTab
+    let title: String
+    let selectedImage: String
+    let unselectedImage: String
+
+    static let defaultItems: [CustomMainTabItem] = [
+        .init(tab: .home, title: "首页", selectedImage: "TabHomeSelected", unselectedImage: "TabHomeUnselected"),
+        .init(tab: .orders, title: "订单", selectedImage: "TabOrderSelected", unselectedImage: "TabOrderUnselected"),
+        .init(tab: .statistics, title: "数据", selectedImage: "TabDataSelected", unselectedImage: "TabDataUnselected"),
+        .init(tab: .profile, title: "我的", selectedImage: "TabProfileSelected", unselectedImage: "TabProfileUnselected")
+    ]
+}
+
+/// 自定义 TabBar 的普通入口按钮。
+private struct CustomMainTabBarItem: View {
+    let item: CustomMainTabItem
+    @Binding var selectedTab: AppTab
+    let badgeText: String?
+
+    private var isSelected: Bool {
+        selectedTab == item.tab
+    }
+
+    var body: some View {
+        Button {
+            selectedTab = item.tab
+        } label: {
+            VStack(spacing: 3) {
+                ZStack(alignment: .topTrailing) {
+                    Image(isSelected ? item.selectedImage : item.unselectedImage)
+                        .renderingMode(.original)
+                        .resizable()
+                        .scaledToFit()
+                        .frame(width: 24, height: 24)
+
+                    if let badgeText {
+                        CustomMainTabBadge(text: badgeText)
+                    }
+                }
+                Text(item.title)
+                    .font(.system(size: 12, weight: isSelected ? .medium : .regular))
+                    .foregroundStyle(isSelected ? AppDesign.primary : Color(hex: 0x7D8DA3))
+                    .lineLimit(1)
+                    .minimumScaleFactor(0.8)
+            }
+            .frame(maxWidth: .infinity)
+            .frame(height: 58)
+            .contentShape(Rectangle())
+        }
+        .buttonStyle(.plain)
+        .accessibilityLabel(item.title)
+    }
+}
+
+/// 自定义 TabBar 中间的扫码核销按钮。
+private struct CustomMainTabBarCenterAction: View {
+    let onScanTap: () -> Void
+
+    var body: some View {
+        Button(action: onScanTap) {
+            ZStack {
+                Circle()
+                    .fill(AppDesign.primary)
+                    .frame(width: 58, height: 58)
+                Image(systemName: "qrcode.viewfinder")
+                    .font(.system(size: 30, weight: .bold))
+                    .foregroundStyle(.white)
+            }
+            .frame(width: 70, height: 64)
+            .contentShape(Circle())
+        }
+        .buttonStyle(.plain)
+        .accessibilityLabel("扫码核销")
+    }
+}
+
+/// 自定义 TabBar 的订单数量角标。
+private struct CustomMainTabBadge: View {
+    let text: String
+
+    var body: some View {
+        Text(text)
+            .font(.system(size: 9, weight: .bold))
+            .foregroundStyle(.white)
+            .frame(minWidth: 15, minHeight: 15)
+            .padding(.horizontal, 2)
+            .background(Color(hex: 0xEF4444), in: Capsule())
+            .offset(x: 9, y: -7)
+    }
+}
+
+#Preview {
+    CustomMainTabBar(
+        selectedTab: .constant(.orders),
+        orderBadgeText: "8",
+        onScanTap: {}
+    )
+}