Add instant payment collection flow aligned with Android.

Implement收款详情与收款记录 pages with pay-code API, QR generation, amount setting, and record grouping so merchants can collect payments from the home quick action.

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

suixinkanTests/PaymentModelsTests.swift

@@ -0,0 +1,53 @@
+//
+//  PaymentModelsTests.swift
+//  suixinkanTests
+//
+
+import XCTest
+@testable import suixinkan
+
+/// 收款模型解码测试。
+final class PaymentModelsTests: XCTestCase {
+    func testPayCodeResponseDecodesSnakeCaseFields() throws {
+        let json = """
+        {
+          "static_pay_url": "https://pay.example.com/static",
+          "dynamic_pay_url": "https://pay.example.com/dynamic"
+        }
+        """.data(using: .utf8)!
+
+        let response = try JSONDecoder().decode(PayCodeResponse.self, from: json)
+
+        XCTAssertEqual(response.staticPayURL, "https://pay.example.com/static")
+        XCTAssertEqual(response.dynamicPayURL, "https://pay.example.com/dynamic")
+    }
+
+    func testRepaymentCollectionRecordResponseDecodesGroupedFields() throws {
+        let json = """
+        {
+          "analyse": [
+            {
+              "date": "2024-01-15",
+              "order_count": 2,
+              "order_amount_sum": "100.00"
+            }
+          ],
+          "list": [
+            {
+              "order_number": "NO001",
+              "user_phone": "13800138000",
+              "order_amount": "50.00",
+              "create_date": "2024-01-15",
+              "create_time": "10:00:00"
+            }
+          ]
+        }
+        """.data(using: .utf8)!
+
+        let response = try JSONDecoder().decode(RepaymentCollectionRecordResponse.self, from: json)
+
+        XCTAssertEqual(response.analyse.count, 1)
+        XCTAssertEqual(response.analyse[0].orderCount, 2)
+        XCTAssertEqual(response.list[0].orderNumber, "NO001")
+    }
+}