Repository health scoring

[arnabnandy7]

Summary

Add repository health scoring to help users evaluate whether a project is active and contributor-friendly.

Motivation

A good issue is more valuable when the repository is maintained, responsive, documented, and welcoming to contributors.

Proposed Scope

• Score repositories using signals such as recent commits, issue response activity, open PR activity, stars, and presence of contribution docs.
• Display repository health on issue cards.
• Use health score as an optional ranking signal.

Acceptance Criteria

• Issue cards show repository health information.
• Health scoring uses multiple repository-level signals.
• Users can distinguish active repositories from stale ones.