feat(notificaciones): mass email notifications over SES

Replaces the four legacy PHP scripts under email.notifications/send*.php
with a single NestJS module. Four jobs (outstanding payments, payment
confirmations, account-status alerts with day-of-week gates, trust
payment confirmations) share one MailService modelled on StorageService:
env-driven SES client, null fallback in dev with console logging, refuses
to send in production when unconfigured.

Schema adds email_notification_log (every attempt, sent/failed/skipped)
and account_status_history (one row per threshold hit, Job 3). Enums
encode the legacy wire shape so external log scrapers keep parsing
notificationType keys verbatim.

Web adds /notificaciones with four trigger cards, a flags panel, and a
paginated log browser. New notification:send ability gates all four
endpoints at MANAGER, matching the renewal:send trust tier.

apps/api/src/mail/mail.module.ts

@@ -0,0 +1,13 @@
+import { Global, Module } from "@nestjs/common";
+import { MailService } from "./mail.service";
+
+/** Global so any feature module can inject MailService without re-importing.
+ *  Matches StorageModule's pattern: the API has one outbound mail transport,
+ *  and gating access behind per-module imports would only add wiring without
+ *  buying isolation. */
+@Global()
+@Module({
+  providers: [MailService],
+  exports: [MailService],
+})
+export class MailModule {}