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/ViewModels/MainTabBadgeViewModel.swift

@@ -0,0 +1,31 @@
+//
+//  MainTabBadgeViewModel.swift
+//  suixinkan
+//
+//  Created by Codex on 2026/6/23.
+//
+
+import Foundation
+import Observation
+
+@MainActor
+@Observable
+/// 主 Tab 角标 ViewModel，负责获取订单 Tab 待核销数量。
+final class MainTabBadgeViewModel {
+    private(set) var pendingWriteOffCount: Int?
+
+    /// 刷新待核销订单数量，缺少景区或接口失败时清空角标。
+    func refreshPendingWriteOffCount(api: OrderServing, scenicId: Int?, storeId: Int?) async {
+        guard let scenicId, scenicId > 0 else {
+            pendingWriteOffCount = nil
+            return
+        }
+
+        do {
+            let result = try await api.writeOffList(scenicId: scenicId, storeId: storeId, page: 1, pageSize: 1)
+            pendingWriteOffCount = min(result.total, 99)
+        } catch {
+            pendingWriteOffCount = nil
+        }
+    }
+}