Add Weighted Rating Calculation

[Naomi-Gift]

Simple averages can over-rank projects with very few reviews.
Acceptance criteria:
Define weighted rating formula.
Add read-only weighted rating getter.
Keep existing average rating for compatibility.
Tests cover low-count and high-count projects.

[manasehstephen131-ops]

@manasehstephen131-ops has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

hello maintainer please i would like to work on this issue i am a Motivated developer experienced in debugging, resolving issues, and contributing to projects. I work with JavaScript, React, Next.js, Node.js, and Rust, and I’m comfortable navigating and improving existing codebases.

Quick to learn, proactive, and focused on delivering quality work.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @manasehstephen131-ops to this issue.

[maztah1]

@maztah1 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

can i solve this issue please

ℹ️ Repo Maintainers: To accept this application, review their application or assign @maztah1 to this issue.

[Goodnessukaigwe]

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

I will like to work on this issue

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

[drips-wave]

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

🧑‍💻 @Goodnessukaigwe: 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

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🤠 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 🌊