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/src/context.ts

@@ -3,8 +3,18 @@
  */
 
 import type { Database } from "@reviq/db-schema";
+import type { EmailClient } from "@reviq/emails";
 import type { Kysely } from "kysely";
 
+/**
+ * Email configuration for the API
+ */
+export interface EmailConfig {
+  client: EmailClient;
+  fromAddress: string;
+  baseUrl: string;
+}
+
 /**
  * Base API context available to all handlers
  */
@@ -23,6 +33,8 @@ export interface APIContext {
   resHeaders: Headers;
   /** Client IP address from direct connection (fallback when no proxy headers) */
   clientIP?: string | null;
+  /** Email client and configuration */
+  email: EmailConfig;
 }
 
 /**