feat(rewards): allocate emissions by repo share

[aliworksx08]

Summary

Closes #1215.

Converts repository allocation from an unbounded per-PR weight multiplier to a bounded per-repository emission_share applied at round aggregation. PR and issue-discovery scores now determine proportional distribution only inside each repository's configured slice.

Changes

• Rename repository allocation config to emission_share while keeping a compatibility alias for existing constructor callers.
• Add issue_discovery_share with default 0.5, plus finite-float and [0, 1] validation.
• Reject registry sums greater than 1.0; registry slack is recycled instead of redistributed.
• Remove repo weighting from PR earned-score, open-PR collateral, and issue-discovery score products.
• Allocate the unified OSS_EMISSION_SHARE = 0.90 scoring pool by repository slice, then split/spill within each repository between PR and issue-discovery sides.
• Route inactive repository slices and registry slack to RECYCLE_UID; keep treasury as flat ISSUES_TREASURY_EMISSION_SHARE = 0.10.
• Migrate master_repositories.json from weight to emission_share.
• Add regression coverage for config invariants, non-finite and boolean share rejection, fixed repo slices across PR counts, PR/issue spill, inactivity recycling, and registry slack.

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other: emission policy change

Testing

• Tests added/updated
• Manually tested

Validation:

uv run pytest tests/validator/test_load_weights.py tests/validator/test_emission_allocation.py tests/validator/oss_contributions/mirror/test_scored_pr.py tests/validator/oss_contributions/mirror/test_scoring.py tests/cli/test_miner_score.py -q
# 158 passed

uv run pytest -q
# 739 passed

uv run ruff check gittensor tests/validator/test_load_weights.py tests/validator/test_emission_allocation.py tests/cli/test_miner_score.py
# All checks passed

uv run ruff format --check gittensor/validator/utils/load_weights.py tests/validator/test_load_weights.py gittensor/validator/forward.py tests/validator/test_emission_allocation.py
# 4 files already formatted

uv run pyright gittensor
# 0 errors, 0 warnings, 0 informations

Checklist

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

[anderdc]

Not advancing for #1215 review. Closing.

[aliworksx08]

@anderdc, excuse me, may I reopen my PR? I don't know why my PR closed.