Extract emails into separate package with clean interface

- Create packages/emails/ with EmailClient interface abstraction
- Wrap Postmark ServerClient in adapter for clean typing
- Add createLoggingEmailClient for dev mode (logs to console)
- Split email templates into individual files with full test coverage
- Update api-server to use new package via context injection
- Remove EMAIL_DEV_MODE - now uses POSTMARK_API_KEY presence
- Delete apps/api-server/src/utils/email.ts

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api-server/package.json

@@ -12,13 +12,13 @@
     "test": "bun test src/ --no-parallel"
   },
   "dependencies": {
-    "@formatjs/intl-durationformat": "^0.9.2",
     "@noble/hashes": "^2.0.1",
     "@orpc/experimental-pino": "^1.13.2",
     "@orpc/server": "^1.13.2",
     "@reviq/api-contract": "workspace:*",
     "@reviq/db": "workspace:*",
     "@reviq/db-schema": "workspace:*",
+    "@reviq/emails": "workspace:*",
     "@reviq/server-utils": "workspace:*",
     "@scure/base": "^2.0.0",
     "@simplewebauthn/server": "^13.2.2",