Add transaction status change notification templates

[nanaf6203-bit]

Provide standardized templates for transaction status notifications.

Acceptance Criteria:

• Notification templates exist for major statuses.
• Templates are used by status update events.
• Users receive clear status change emails.
• Tests verify template rendering and selection.

[Michael997glitch]

@Michael997glitch has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi, I’m a smart contract and a full-stack web developer, I have read through the issue and it’s something I’m capable of doing. Please assign me this work.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Michael997glitch to this issue.

[sandrawillow001-afk]

@sandrawillow001-afk has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

can i work on this issue sir

ℹ️ Repo Maintainers: To accept this application, review their application or assign @sandrawillow001-afk to this issue.

[drips-wave]

Congratulations, @sandrawillow001-afk! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @sandrawillow001-afk: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊

[drips-wave]

This issue has been completed by @sandrawillow001-afk as part of the Stellar Wave Program's 5th Wave 🥳

😎 @sandrawillow001-afk: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

🧑‍💻 Repo maintainers: How'd the contributor do? Leave a review to share your experience working with them.