feat(planning): reward-risk severity taxonomy, opportunity factors, eligibility gap (#816)

[oktofeesh1]

Summary

Implements the three deliverables from issue #816 (fold upstream-inspired advisor/scan ideas into gittensory miner planning):

• Action severity taxonomy — RewardRiskAction now carries severity: "critical" | "warning" | "tip" | "info". critical = score gate is blocked by at least one scoreBlocker; warning = active penalty (cleanup pressure or closed-PR rate); tip = multiplier opportunity; info = planning context / maintainer lane.
• Opportunity factors — RepoRewardRisk.rewardUpside gains opportunityFactors: { competitionFactor, freshnessFactor }. competitionFactor = ratio of high-risk duplicate clusters to open PRs (0 = open field, 1 = fully contested). freshnessFactor decays exponentially with the age of the most-recently-updated open issue (~1.0 at 0 d, ~0.6 at 7 d, ≤0.05 at 90 d).
• Eligibility gap view — ContributorRewardRiskStrategy gains eligibilityGap: EligibilityGapEntry[] listing contributor repos where landing or withdrawing 1–5 open PRs would flip the open-PR gate toward scoreable, sorted by fewest cleanups needed (≤5 entries).

OpenAPI schema regenerated (ui:openapi). local-branch.ts waitAction updated with the required severity field. Three new test blocks in signals-coverage.test.ts cover both sides of every new branch (cleanupNeeded > 0, hasBlockers, freshness decay, closed-issue exclusion, null-date fallback, eligibility threshold 1–5 vs 0 vs >5).

Scope

• src/ changes only — no site/, CNAME, or **/lovable/**
• OpenAPI JSON regenerated and committed
• No secrets, tokens, wallets, trust scores, or payout values

Validation

• npm run typecheck — clean
• npm run test:ci — all 3768 tests pass, exit 0
• npm run ui:openapi:check — passes (JSON regenerated)

Safety

• No auth/session/CORS changes
• No secrets or private scoring values in code, tests, or this PR text
• close_or_withdraw_low_fit_prs action fires only for contributor (non-maintainer) lane

Closes #816

[superagent-security]

Superagent didn't find any vulnerabilities or security issues in this PR.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.43%. Comparing base (1b7c72c) to head (1def9aa).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1351      +/-   ##
==========================================
+ Coverage   95.42%   95.43%   +0.01%     
==========================================
  Files         193      193              
  Lines       21026    21044      +18     
  Branches     7614     7618       +4     
==========================================
+ Hits        20064    20084      +20     
  Misses        383      383              
+ Partials      579      577       -2     

Files with missing lines	Coverage Δ
src/openapi/schemas.ts	100.00% <ø> (ø)
src/signals/local-branch.ts	97.19% <ø> (ø)
src/signals/reward-risk.ts	96.52% <100.00%> (+1.23%)	⬆️

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[JSONbored]

Screen: ✅ Wanted. #816 is owner-authored, OPEN, gittensor:feature+roadmap; planning signals are core to the maintainer-agent thesis. One coherent subsystem (5 files), real value, low risk. Verdict: MERGE · gittensor:feature. Three deliverables map clause-by-clause to #816, OpenAPI regenerated, both-branch tests, green.