[Frontend] Implement Notification Delivery Heatmap

[Abd-Standard]

Description

Build a visual heatmap that helps organizations understand notification activity patterns across different days and time periods.

Tasks
Create heatmap component.
Aggregate delivery activity data.
Add date range filtering.
Support dark and light themes.
Optimize rendering performance.

Acceptance Criteria
Heatmap displays delivery activity accurately.
Filters update visualization correctly.
Component remains responsive on mobile devices.

[misrasamuelisiguzor-oss]

@misrasamuelisiguzor-oss has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I’m a smart contract developer who turns complex ideas into secure, production-ready blockchain code.
With strong skills in Rust and Solidity, I build systems that are fast, safe, and built to last.
My experience with the Stellar SDK lets me ship real-world Web3 solutions that actually move value

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

[Adeswalla]

@Adeswalla has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hello Maintainer,
I would like to apply for this issue

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

[grantfox-oss]

🦊 GrantFox — @Adeswalla has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #185)
2. Your PR will be reviewed by the Core-Foundry maintainers

Good luck! Track your progress on GrantFox.

[drips-wave]

Congratulations, @Adeswalla! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @Adeswalla: 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 🌊

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox!

@Adeswalla's PR #212 was approved and merged by @Abd-Standard.

🏆 @Adeswalla: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (331 total points). Track your full progress on GrantFox.

👏 Great work, @Adeswalla! Keep contributing to Core-Foundry.