feat(rewards): allocate OSS emissions by repository emission share

[gazeatcode]

Summary

• Implements issue Convert per-repo weight from unbounded multiplier to emission_share (bounded pool slice) #1215 with bounded per-repo allocation via emission_share and per-repo PR/issue split via issue_discovery_share.
• Removes repo weight from per-PR multiplier behavior in active scoring paths (repo multipliers are neutralized to 1.0 and allocation is enforced at emission blending).
• Collapses top-level emissions to scoring pool + treasury (OSS_EMISSION_SHARE = 0.90, ISSUES_TREASURY_EMISSION_SHARE = 0.10) and routes recycle through allocation-time slack/inactivity behavior.
• Adds share-bound and sum-bound validation for repository config loading.
• Migrates master_repositories.json from weight to emission_share and adds issue_discovery_share.
• Adds allocation and invariant coverage tests.

Related Issues

Closes #1215

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other (describe below)

Testing

• Tests added/updated
• Manually tested

Commands run:

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
uv run ruff check gittensor/validator/utils/load_weights.py gittensor/validator/forward.py tests/validator/test_load_weights.py tests/validator/test_emission_allocation.py
uv run ruff format --check gittensor/validator/utils/load_weights.py gittensor/validator/forward.py tests/validator/test_load_weights.py tests/validator/test_emission_allocation.py

Checklist

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

Context

This PR consolidates and republishes the strongest candidate from prior attempts:

• Feat/emission share allocation #1216
• feat(rewards): allocate emissions by repo share #1217
• feat(rewards): allocate OSS emissions by repository emission share #1219

under the gazeatcode fork/account with a single clean commit.

[anderdc]

Duplicate of #1219 (identical diff). Closing.