feat(planning): fold upstream-inspired advisor/scan ideas into gittensory miner planning

[JSONbored]

Inspiration from upstream gittensor issue #1460 (see #813) — our own implementation, not a copy of any command. Three ideas worth folding into gittensory's native miner planning:

Deliverables

• Severity-grouped advice — layer a CRITICAL / WARNING / TIP / INFO taxonomy onto our existing reward-risk + decision-pack output: CRITICAL = eligibility blockers, WARNING = active penalties (open-PR spam, time-decay past midpoint, review penalty), TIP = multiplier opportunities (missing issue link, unused label multiplier, issue-discovery = 0), INFO = planning context (decay trajectory, diversification). Makes the advice scannable + action-first.
• Explicit opportunity factors — surface competition_factor (competing open PRs — reuse our collision/duplicate detection) and freshness_factor (issue age) as named components of the reward-risk opportunity score, alongside emission_share × label × issue multipliers we already model.
• Eligibility-gap view — a cross-repo 'repos within N PRs of eligibility unlock' surface, built on our scenario projections + cross-repo federation ([Feature]: Cross-repo queue health federation and comparative pressure index #479). Tells a miner where a few PRs flip a repo to eligible.

Context

src/signals/reward-risk.ts, src/services/decision-pack.ts, src/scoring/preview.ts (scenario previews). Relates #544 (miner intelligence), #479 (federation), #805 (PMF funnel — sharper advice helps onboarding).

Outcome

gittensory's miner planning gives crisper, severity-ranked, action-first guidance — our differentiated take, surfaced across MCP / dashboard / extension. No command copying; we fold the concepts in where they fit.