feat: add notification triggers, comment roles, mention list, and static file serving

- Notify users on ticket assignment and remittance confirm/reject
- Add collector role to comment endpoints
- Add /users/mention-list endpoint for @mention support
- Serve uploaded files via express.static

src/payment/payment.controller.ts

@@ -42,8 +42,10 @@ export class PaymentController {
 
   @Get('unremitted')
   @Roles('technician', 'collector')
-  async getUnremitted(@CurrentUser() user: CurrentUserPayload, @Query('collectorId') collectorId?: string) {
-    return this.paymentService.getUnremittedPayments(user.tenantId, collectorId || user.sub);
+  async getUnremitted(@CurrentUser() user: CurrentUserPayload, @Query('all') all?: string) {
+    const isManager = user.roles?.some((r: string) => ['manager', 'tenant_admin', 'super_admin'].includes(r));
+    // Managers see all unremitted; collectors see only their own
+    return this.paymentService.getUnremittedPayments(user.tenantId, isManager ? null : user.sub);
   }
 
   @Get('remittances')