Fix: `MaintainerActive` Signal Is Never Set — Repos Always Lose 20 Points

[Vedant1703]

The scoring engine (engine.go) awards 20 points when the MaintainerActive signal is true. However, looking at signals.go, the MaintainerActive field is never assigned — it stays at its zero value (false) for every single repository.

This means every repository recommendation silently loses 20 points regardless of actual maintainer activity, making scores consistently lower than intended.

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📍 File to Change

backend/core_service/internal/orchestration/signals.go

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🔍 Current Buggy Code (lines ~10–40 in signals.go)

// MaintainerActive is NEVER set — always stays false
func (s *Service) BuildRepoSignals(...) scoring.RepoSignals {
    signals := scoring.RepoSignals{}
    
    repoData, err := s.githubClient.FetchRepo(ctx, repo)
    // ... MaintainerActive is never touched here
    
    return signals
}

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✅ What To Do

After fetching repoData, add a heuristic check: if the repo was pushed to within the last 7 days, consider the maintainer active.

// Add this block after the RecentActivity check in signals.go:

// Check if maintainer is active (pushed within last 7 days)
pushedTime, err := time.Parse(time.RFC3339, repoData.LastPushedAt)
if err == nil && time.Since(pushedTime).Hours() < 24*7 {
    signals.MaintainerActive = true
}

Add a brief comment explaining the heuristic so future contributors understand the logic.

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🏁 Acceptance Criteria

• signals.MaintainerActive is now set to true when the repo was pushed to within the last 7 days
• The existing signals.RecentActivity check (30-day threshold) is untouched
• The code compiles: go build ./... from backend/core_service must pass
• A short comment documents the heuristic (e.g., // Active maintainer: pushed within last 7 days)

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💡 Technical Hints

• Edit backend/core_service/internal/orchestration/signals.go — specifically the BuildRepoSignals function
• repoData.LastPushedAt is a string formatted as RFC3339 — parse it using time.Parse(time.RFC3339, ...)
• The same parsing pattern is already used a few lines above for RecentActivity — follow the same style
• You do not need to make any new API calls; repoData is already fetched

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🚀 Getting Started

1. Fork the repository
2. Create a branch: git checkout -b fix/issue-3-maintainer-active-signal
3. Edit backend/core_service/internal/orchestration/signals.go
4. Verify it compiles: cd backend/core_service && go build ./...
5. Open a Pull Request!