feat: Implement Phase 10 support and recommendations features

- Added models for support messages, SLA policies, tickets, ticket events, and ticket links.
- Created routes for help, help admin, newsletter, recommendations, and support for both customer and admin.
- Developed services for help, marketing (newsletter), and recommendations.
- Introduced support service for ticket management, including creation, replies, transitions, and attachments.
- Added validation schemas for support recommendations and ticket management.
- Implemented a cron job for support reconciliation and recommendation cleanup.
- Created migration for new support and recommendation database tables.
- Added unit tests for validation and policy checks related to Phase 10 features.

app/models/marketing/newsletterSubscription.model.js

@@ -0,0 +1 @@
+module.exports=(s,D)=>s.define("NewsletterSubscription",{id:{type:D.STRING,primaryKey:true},email_normalized:{type:D.STRING(254),allowNull:false,unique:true},user_id:D.STRING,status:{type:D.ENUM("PENDING","SUBSCRIBED","UNSUBSCRIBED"),allowNull:false},locale:{type:D.ENUM("en","si","ta"),allowNull:false,defaultValue:"en"},source:{type:D.ENUM("HOME_FOOTER","CHECKOUT","ACCOUNT","ADMIN_IMPORT"),allowNull:false},consented_at:D.DATE,confirmed_at:D.DATE,unsubscribed_at:D.DATE,unsubscribe_token_hash:{type:D.STRING(64),allowNull:false}},{tableName:"newsletter_subscriptions",timestamps:true});