fix(notificaciones): merge renewals into one screen, fix MailModule DI

MailModule's provider used a `useFactory` with no `inject`, so the factory
received `undefined` and `new MailService(config)` threw on `config.get`,
taking the whole API down at boot. The module also wasn't actually
`@Global()` even though both NotificationsModule and RenewalsModule inject
MailService without importing it — that would have failed next. Replaced the
factory with a plain provider (ConfigModule is already `isGlobal`) and marked
the module global.

On the web side, mass email and renewal notices were two menu entries doing
the same job — telling a customer something by email. They are now two tabs
of `/notificaciones` (Servicios and Pólizas), following the Captura pattern:
`/renovaciones` still resolves, opening the same screen on its Pólizas tab so
existing bookmarks keep working.

The notifications page was also the last screen written in raw inline styles,
with blue buttons and filter pills that appear nowhere else in the app. It now
uses the shared design system: btn-primary/btn-outline, the seg segmented
control, card, tx-table, pager, and the servicios/fideicomiso badges.

Two supporting fixes found on the way: NOTIFICATION_STATUS_COLORS hardcoded
hex instead of the theme's positive/negative/muted vars, and `.small` was
referenced in 19 places across the app but never defined in globals.css.

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

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

@@ -1,12 +1,13 @@
-import { Module } from "@nestjs/common";
-import { ConfigService } from "@nestjs/config";
+import { Global, Module } from "@nestjs/common";
 import { MailService } from "./mail.service";
 
 /** Global so any feature module can inject MailService without re-importing.
  *  Matches the StorageService pattern: env-driven, null when unconfigured,
- *  and never blocks API boot. Notifications use it; renewals reuse it. */
+ *  and never blocks API boot. Notifications use it; renewals reuse it.
+ *  ConfigService comes from the global ConfigModule in AppModule. */
+@Global()
 @Module({
-  providers: [{ provide: MailService, useFactory: (c: ConfigService) => new MailService(c) }],
+  providers: [MailService],
   exports: [MailService],
 })
 export class MailModule {}