feat(validator): add OSS-scoring round completion summary

[Khaostica]

Summary

The issue-discovery phase closes each scoring round with a one-line summary (Issue discovery complete | N processed | … in scan.py), but the OSS-scoring phase logs only Finalization complete. with no round-level aggregate. This change adds the matching completion summary so an operator can gauge a scoring round at a glance.

Additive logging only: it reads is_eligible / failed_reason (already set during finalization) plus the cached_uids / penalized_uids sets that get_rewards() already holds. It only counts and prints values that already exist — no scoring logic runs, and no miner's score changes.

Before — the OSS-scoring phase ended here, with no round-level summary:

Finalization complete.

After — a single summary line now follows it (the counts below are from an example round, included to show the format — not real validator output):

Finalization complete.

OSS scoring complete | 40 evaluated | 22 eligible | 2 penalized (duplicate github) | 5 cache-fallback | 1 failed validation

Related Issues

Closes #1400

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other

Testing

• Tests added/updated
• Manually tested

$ pytest tests/validator/test_oss_scoring.py -v
collected 2 items

tests/validator/test_oss_scoring.py::TestLogOssScoringSummary::test_counts_each_category PASSED [ 50%]
tests/validator/test_oss_scoring.py::TestLogOssScoringSummary::test_empty_round_reports_zeros PASSED [100%]

============================== 2 passed in 0.12s ==============================

$ ruff check gittensor/validator/oss_contributions/scoring.py gittensor/validator/oss_contributions/reward.py tests/validator/test_oss_scoring.py
All checks passed!

$ ruff format --check gittensor/validator/oss_contributions/scoring.py gittensor/validator/oss_contributions/reward.py tests/validator/test_oss_scoring.py
3 files already formatted

Checklist

• Code follows project style guidelines
• Self-review completed
• Changes are documented (if applicable)