feat(crm): add event_reminder_* templates to dev email tester

The pre-event reminder feature shipped with 5 seeded templates
(event_reminder_default + wedding/birthday/corporate/other) but the
CRM → Development "Send any CRM email to me" picker only listed the
quote/invoice/contract templates. Maintainer can now eyeball each
reminder category's body without staging a real event.

Backend:
- Extend TEMPLATES_KEYS in adminDev.js with all 5 reminder keys.
- Add event_date (today+2d), days_before (2), business_name (from
  business_profile.legal_name) to the common payload so the
  {{tokens}} in the reminder bodies resolve.

Frontend:
- Extend CrmEmailTemplateKey union.
- Add TEMPLATE_LABEL_KEYS entries.
- EN+DE i18n labels under crmDev.templates.label.event_reminder_*.

No PDF attachment — reminders are body-only emails (matches the
real flow).

frontend/src/services/devTools.service.ts

@@ -22,7 +22,16 @@ export type CrmEmailTemplateKey =
   // template_key strings.
   | 'contract_sent'
   | 'contract_signed_admin_notification'
-  | 'contract_fully_signed';
+  | 'contract_fully_signed'
+  // Pre-event reminder emails (migration 143). One template per
+  // event_type with a catch-all default. Backend resolves
+  // `event_reminder_<event_type>` then falls back to
+  // `event_reminder_default`.
+  | 'event_reminder_default'
+  | 'event_reminder_wedding'
+  | 'event_reminder_birthday'
+  | 'event_reminder_corporate'
+  | 'event_reminder_other';
 
 export interface DevEmailTemplateStatus {
   key: CrmEmailTemplateKey;