feat: add Delivered status to notification enums

- Add Delivered status to BillsNotificationStatus enum
- Add Delivered status to RentNotificationStatus enum
- Update JSDoc comments for clarity
- Delivered status will be set by webhook when email is confirmed delivered

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

shared-code/src/db-types.ts

@@ -57,11 +57,13 @@ export enum BillsNotificationStrategy {
 }
 
 export enum BillsNotificationStatus {
-    /** Bills notification is scheduled to be sent */
+    /** notification is scheduled to be sent */
     Scheduled = "scheduled",
-    /** Bills notification has been sent */
+    /** notification has been sent */
     Sent = "sent",
-    /** Sending of bills notification failed */
+    /** notification has been successfully delivered (set by webhook) */
+    Delivered = "delivered",
+    /** Sending of notifications failed */
     Failed = "failed",
     /** Email to tenant has bounced (set by webhook) */
     Bounced = "bounced"
@@ -70,6 +72,8 @@ export enum BillsNotificationStatus {
 export enum RentNotificationStatus {
     /** notification has been sent */
     Sent = "sent",
+    /** notification has been successfully delivered (set by webhook) */
+    Delivered = "delivered",
     /** Sending of notification failed */
     Failed = "failed",
     /** Email to tenant has bounced (set by webhook) */