feat(discount): apply rule-based discounts on the session payment step

PaymentStep now loads /session/{uuid}/discount-suggestions and lets the
operator apply a suggested rule (PATCH discount_rule_uuid) or remove it,
alongside the existing manual discount. Adds an amount summary (before /
discount + source rule label / final payable). Verified end-to-end.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

assets/admin/components/SessionServiceCard.tsx

@@ -27,6 +27,7 @@ export interface SessionCardData {
   discount_type?: 'percent' | 'fixed' | null;
   discount_value?: number;
   discount_rials?: number;
+  applied_discount_rule_label?: string | null;
   paid_total_rials?: number;
   paid_at?: number | null;
   payments?: SessionPaymentEntry[];

assets/admin/components/session/PaymentStep.tsx

@@ -1,9 +1,11 @@
 import { useState } from 'react';
-import { useMutation, useQueryClient } from '@tanstack/react-query';
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 import { ChevronDownIcon } from '@heroicons/react/24/outline';
 import { toast } from 'sonner';
 import { api } from '../../lib/api';
+import type { ApiResponse } from '../../lib/api';
 import { formatRial } from '../../lib/utils';
+import type { DiscountSuggestion } from '../../types';
 import type { SessionCardData } from '../SessionServiceCard';
 import SearchableSelect from '../ui/SearchableSelect';
 import PersianDateInput from '../ui/PersianDateInput';
@@ -54,6 +56,7 @@ export default function PaymentStep({ recordUuid, session, walletBalance, onCont
   const invalidate = () => {
     qc.invalidateQueries({ queryKey: ['patient-sessions', recordUuid] });
     qc.invalidateQueries({ queryKey: ['patient-wallet', recordUuid] });
+    qc.invalidateQueries({ queryKey: ['discount-suggestions', sessionUuid] });
   };
 
   const discountMut = useMutation({
@@ -68,13 +71,22 @@ export default function PaymentStep({ recordUuid, session, walletBalance, onCont
     onError: (e: Error) => toast.error(e.message),
   });
 
+  const suggestionsQ = useQuery({
+    queryKey: ['discount-suggestions', sessionUuid],
+    queryFn: () => api.get<ApiResponse<DiscountSuggestion[]>>(`/api/v1/session/${sessionUuid}/discount-suggestions`),
+  });
+  const suggestions: DiscountSuggestion[] = (suggestionsQ.data?.data as any)?.data ?? (suggestionsQ.data?.data as any) ?? [];
+
   const applyDiscount = () => {
     if (!discountType || !discountValue) return;
     discountMut.mutate({ discount_type: discountType, discount_value: Number(discountValue) });
   };
+  const applyRule = (ruleUuid: string) => {
+    discountMut.mutate({ discount_rule_uuid: ruleUuid });
+  };
   const removeDiscount = () => {
     setDiscountType(''); setDiscountValue('');
-    discountMut.mutate({ discount_type: null });
+    discountMut.mutate({ discount_rule_uuid: null });
   };
   const submitPayment = (method: string) => {
     if (!amount) return;
@@ -85,6 +97,8 @@ export default function PaymentStep({ recordUuid, session, walletBalance, onCont
   const discountRials = session.discount_rials ?? 0;
   const debt = session.patient_debt_rials ?? 0;
   const payments = session.payments ?? [];
+  const appliedRuleLabel = session.applied_discount_rule_label ?? null;
+  const payable = Math.max(0, finalPrice - discountRials);
 
   return (
     <>
@@ -95,6 +109,31 @@ export default function PaymentStep({ recordUuid, session, walletBalance, onCont
         <span className="dark:text-[#D7D8ED]" style={{ fontSize: 14, fontWeight: 700, color: '#525252' }}>{formatRial(finalPrice)}</span>
       </div>
 
+      {/* تخفیف‌های پیشنهادی (قوانین تخفیف) */}
+      {suggestions.length > 0 && (
+        <div className="dark:border-[#35343D]" style={{ border: '1px solid #E8EBFF', background: '#F7F8FF', borderRadius: 8, padding: 12, marginBottom: 16 }}>
+          <span style={{ ...fieldLabel, marginBottom: 10, fontWeight: 600, color: '#3B3F9F' }}>تخفیف‌های قابل اعمال:</span>
+          <div style={{ display: 'flex', flexDirection: 'column', gap: 8 }}>
+            {suggestions.map((s) => (
+              <div key={s.rule_uuid} style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', gap: 8 }}>
+                <span className="dark:text-[#D7D8ED]" style={{ fontSize: 13, color: '#374151' }}>
+                  {s.rule_name} — <span style={{ color: '#D32F2F' }}>{formatRial(s.discount_rials)}</span>
+                  {' '}<span style={{ color: '#6B7280', fontSize: 12 }}>({s.discount_type === 'percent' ? `${s.value}٪` : 'مبلغ ثابت'})</span>
+                </span>
+                <button
+                  type="button"
+                  onClick={() => applyRule(s.rule_uuid)}
+                  disabled={discountMut.isPending}
+                  style={{ height: 32, minWidth: 64, border: 'none', borderRadius: 6, background: '#5559CE', color: '#fff', fontSize: 12.5, fontWeight: 600, cursor: 'pointer' }}
+                >
+                  اعمال
+                </button>
+              </div>
+            ))}
+          </div>
+        </div>
+      )}
+
       {/* تخفیف — port of tauri DiscountInput (نوع + مقدار + ثبت) */}
       <span style={fieldLabel}>تخفیف:</span>
       <div style={{ display: 'flex', alignItems: 'stretch', gap: 8 }}>
@@ -134,10 +173,21 @@ export default function PaymentStep({ recordUuid, session, walletBalance, onCont
         </div>
       </div>
 
-      <p style={{ fontSize: 13, marginBottom: 16 }}>
-        <span className="dark:text-[#D7D8ED]" style={{ color: '#2f2f2f' }}>مبلغ تخفیف:</span>{' '}
-        <span style={{ color: '#D32F2F' }}>{formatRial(discountRials)}</span>
-      </p>
+      {/* خلاصه‌ی مبلغ: قبل از تخفیف / تخفیف / نهایی / منبع */}
+      <div className="dark:border-[#35343D]" style={{ border: '1px solid #e0e0e0', borderRadius: 8, padding: 12, marginBottom: 16, display: 'flex', flexDirection: 'column', gap: 6 }}>
+        <div style={{ display: 'flex', justifyContent: 'space-between', fontSize: 13 }}>
+          <span className="dark:text-[#A1A1A1]" style={{ color: '#6B7280' }}>مبلغ قبل از تخفیف:</span>
+          <span className="dark:text-[#D7D8ED]" style={{ color: '#2f2f2f' }}>{formatRial(finalPrice)}</span>
+        </div>
+        <div style={{ display: 'flex', justifyContent: 'space-between', fontSize: 13 }}>
+          <span className="dark:text-[#A1A1A1]" style={{ color: '#6B7280' }}>مبلغ تخفیف{appliedRuleLabel ? ` (${appliedRuleLabel})` : ''}:</span>
+          <span style={{ color: '#D32F2F' }}>{formatRial(discountRials)}</span>
+        </div>
+        <div style={{ display: 'flex', justifyContent: 'space-between', fontSize: 13, fontWeight: 700, borderTop: '1px dashed #e0e0e0', paddingTop: 6 }}>
+          <span className="dark:text-[#D7D8ED]" style={{ color: '#2f2f2f' }}>مبلغ نهایی قابل پرداخت:</span>
+          <span className="dark:text-[#D7D8ED]" style={{ color: '#2f2f2f' }}>{formatRial(payable)}</span>
+        </div>
+      </div>
 
       {/* تاریخ پرداخت */}
       <span className="dark:text-[#A1A1A1]" style={{ ...fieldLabel, color: '#3b3b3b' }}>تاریخ پرداخت</span>