feat: add platform invoice dunning workflow

apps/taro/src/pages/platform-admin/billing/index.tsx

@@ -7,11 +7,14 @@ import {
   createPlatformInvoiceFromSubscription,
   createPlatformInvoicesBatchFromSubscriptions,
   createPlatformSubscription,
+  loadPlatformInvoiceReminders,
   loadPlatformInvoices,
   loadPlatformPlans,
   loadPlatformSubscriptionInvoiceCandidates,
   loadPlatformUsage,
+  processPlatformOverdueInvoices,
   recordPlatformUsage,
+  type PlatformInvoiceReminderItem,
   type PlatformInvoiceItem,
   type PlatformSaasPlan,
   type PlatformSubscriptionInvoiceCandidate,
@@ -38,6 +41,7 @@ export default function PlatformBillingPage() {
   const [status, setStatus] = useState('');
   const [plans, setPlans] = useState<PlatformSaasPlan[]>([]);
   const [invoices, setInvoices] = useState<PlatformInvoiceItem[]>([]);
+  const [reminders, setReminders] = useState<PlatformInvoiceReminderItem[]>([]);
   const [usage, setUsage] = useState<PlatformUsageItem[]>([]);
   const [candidates, setCandidates] = useState<PlatformSubscriptionInvoiceCandidate[]>([]);
   const [batchResult, setBatchResult] = useState('');
@@ -77,13 +81,15 @@ export default function PlatformBillingPage() {
     Promise.all([
       loadPlatformPlans(true).catch(() => ({ items: [] })),
       loadPlatformInvoices({ status: nextStatus || undefined, limit: 100 }),
+      loadPlatformInvoiceReminders({ limit: 80 }).catch(() => ({ items: [] })),
       loadPlatformUsage({ limit: 80 }).catch(() => ({ items: [] })),
       loadPlatformSubscriptionInvoiceCandidates({ daysAhead: Number(batchInvoiceForm.daysAhead || 45), limit: 100 }).catch(() => ({ items: [] })),
-    ]).then(([planPayload, invoicePayload, usagePayload, candidatePayload]) => {
+    ]).then(([planPayload, invoicePayload, reminderPayload, usagePayload, candidatePayload]) => {
       const nextPlans = planPayload.items || [];
       setPlans(nextPlans);
       setSubscriptionForm(current => ({ ...current, planCode: current.planCode || nextPlans[0]?.code || '' }));
       setInvoices(invoicePayload.items || []);
+      setReminders(reminderPayload.items || []);
       setUsage(usagePayload.items || []);
       setCandidates(candidatePayload.items || []);
     }).catch(nextError => setError(nextError instanceof Error ? nextError.message : '账务数据加载失败'));
@@ -283,6 +289,32 @@ export default function PlatformBillingPage() {
     }
   }
 
+  async function submitOverdueProcess(dryRun: boolean) {
+    setError('');
+    const ok = dryRun
+      ? true
+      : await confirm('处理逾期账单', '确认扫描已过期未结清的平台服务费账单，并生成内部催缴记录？该动作不会自动停用租户。');
+    if (!ok) return;
+    setBusy(dryRun ? 'overdue-dry-run' : 'overdue-process');
+    try {
+      const payload = await processPlatformOverdueInvoices({
+        dryRun,
+        channel: 'internal',
+        limit: 100,
+      });
+      const item = payload.item || {};
+      setBatchResult(`${dryRun ? '逾期预览' : '逾期处理'}完成：处理 ${item.processed || 0}，标记 ${item.markedOverdue || 0}，催缴 ${item.reminderCreated || 0}，跳过 ${item.skippedReminder || 0}`);
+      if (!dryRun) {
+        Taro.showToast({ title: '已处理', icon: 'success' });
+        reload(status);
+      }
+    } catch (nextError) {
+      setError(nextError instanceof Error ? nextError.message : '逾期处理失败');
+    } finally {
+      setBusy('');
+    }
+  }
+
   return (
     <View className='platform-page'>
       <View className='platform-shell'>
@@ -381,6 +413,25 @@ export default function PlatformBillingPage() {
           {!candidates.length ? <View className='platform-empty'>暂无即将到期且未开票的订阅。</View> : null}
         </View>
 
+        <View className='platform-section'>
+          <Text className='platform-section-title'>逾期与催缴</Text>
+          <View className='platform-actions'>
+            <Button className='platform-button' loading={busy === 'overdue-dry-run'} onClick={() => submitOverdueProcess(true)}>预览逾期</Button>
+            <Button className='platform-button primary' loading={busy === 'overdue-process'} onClick={() => submitOverdueProcess(false)}>生成催缴</Button>
+          </View>
+          <View className='platform-list'>
+            {reminders.slice(0, 12).map(item => (
+              <View className='platform-row' key={item.id}>
+                <Text className='platform-row-main'>{item.invoiceNo || item.invoiceId}</Text>
+                <Text className='platform-row-meta'>{item.tenantName || item.tenantSlug || item.tenantId} · {item.reminderType || 'reminder'} · {item.channel || 'internal'} · {item.status || '-'}</Text>
+                <Text className='platform-row-meta'>第 {String(item.reminderLevel || 1)} 次 · 账单到期 {item.dueDate ? String(item.dueDate).slice(0, 10) : '-'} · 快照余额 {money(item.balanceCentsSnapshot)}</Text>
+                <Text className='platform-row-meta'>{item.message || '暂无催缴备注'}</Text>
+              </View>
+            ))}
+          </View>
+          {!reminders.length ? <View className='platform-empty'>暂无催缴记录。</View> : null}
+        </View>
+
         <View className='platform-section'>
           <Text className='platform-section-title'>SaaS 套餐</Text>
           <View className='platform-list'>

apps/taro/src/services/platformAdmin.ts

@@ -126,6 +126,24 @@ export interface PlatformInvoiceItem {
   note?: string | null;
 }
 
+export interface PlatformInvoiceReminderItem {
+  id: string;
+  tenantId: string;
+  tenantSlug?: string | null;
+  tenantName?: string | null;
+  invoiceId: string;
+  invoiceNo?: string | null;
+  reminderType?: string | null;
+  channel?: string | null;
+  status?: string | null;
+  reminderDate?: string | null;
+  reminderLevel?: number | string | null;
+  dueDate?: string | null;
+  balanceCentsSnapshot?: number | string | null;
+  message?: string | null;
+  createdAt?: string | null;
+}
+
 export interface PlatformUsageItem {
   id: string;
   tenantId: string;
@@ -265,6 +283,12 @@ export interface ConfirmPlatformInvoicePaymentInput {
   providerTradeNo?: string;
 }
 
+export interface ProcessPlatformOverdueInvoicesInput {
+  dryRun?: boolean;
+  channel?: string;
+  limit?: number;
+}
+
 export interface RecordPlatformUsageInput {
   tenantId: string;
   metricKey: string;
@@ -417,6 +441,34 @@ export async function confirmPlatformInvoicePayment(input: ConfirmPlatformInvoic
   });
 }
 
+export async function processPlatformOverdueInvoices(input: ProcessPlatformOverdueInvoicesInput = {}) {
+  return apiRequest<{
+    item?: {
+      dryRun?: boolean;
+      processed?: number;
+      markedOverdue?: number;
+      reminderCreated?: number;
+      skippedReminder?: number;
+      items?: Array<PlatformInvoiceItem & {
+        wouldMarkOverdue?: boolean;
+        wouldCreateReminder?: boolean;
+        reminderCreated?: boolean;
+      }>;
+    };
+  }>('/api/platform-admin/invoices/process-overdue', {
+    method: 'POST',
+    body: input,
+    tenantId: null,
+  });
+}
+
+export async function loadPlatformInvoiceReminders(query: { tenantId?: string; invoiceId?: string; status?: string; reminderType?: string; limit?: number } = {}) {
+  return apiRequest<{ items?: PlatformInvoiceReminderItem[] }>('/api/platform-admin/invoices/reminders', {
+    query: { ...query, limit: query.limit || 100 },
+    tenantId: null,
+  });
+}
+
 export async function recordPlatformUsage(input: RecordPlatformUsageInput) {
   return apiRequest<{ item?: Record<string, unknown> }>('/api/platform-admin/usage', {
     method: 'POST',