Issue + Replies + Stars + Organization for Calendar (More To Come After AP Exam)

[SanPranav]

• Issue Comment Notifications: When a user posts a reply on an issue, the issue owner receives an email notification (recipient pulled from Person database)
• Starred Issue Followers: All users who starred an issue receive an email notification when new comments are posted (excluding the commenter)
• FormSubmit Email Delivery: Uses FormSubmit for email sending—no server credentials required, fully deployment-safe
• Database-Driven Recipients: All recipient emails resolved from Person database (UID/name/email-map lookup)
• Fixed Star Toggle: Robust unstar functionality via entity-based deletion instead of signature-based delete
• Deployment Ready: Zero .env file dependencies; Origin/Referer headers default to production domain; works on localhost and deployed environments
• Diagnostic Logging: Added [Email] and [EmailNotificationService] logs to trace email delivery flow
• Configurable Endpoints: FormSubmit endpoint supports ${VAR:default} placeholder expansion for flexibility