feat: show this month's birthdays and send a greeting SMS

Each owner sees their customers born this Jalali month and can text a custom greeting.

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

apps/api/src/contacts/dto.ts

@@ -17,6 +17,13 @@ import {
 } from 'class-validator';
 import { PERSON_IMPORT_SOURCES, PERSON_MOODS } from '@mento/shared';
 
+export class BirthdaySmsDto {
+  @IsString()
+  @MinLength(1)
+  @MaxLength(500)
+  text!: string;
+}
+
 export class BulkDeletePeopleDto {
   @IsArray()
   @ArrayMinSize(1)