feat(github-agent): add maintainer digest and queue commands

[JSONbored]

Background

Maintainers need queue-level context, not just per-PR comments. Mention commands should answer what to review now and what needs author action.

Goal

Add maintainer-only commands for queue summaries, confirmed-miner PRs, review-now candidates, needs-author PRs, and duplicate clusters.

Current Behavior

Maintainer intelligence exists in private packets/signals, but is not exposed through safe command workflows.

Desired Behavior

A maintainer can invoke Gittensory from GitHub and get a concise, safe queue digest.

Implementation Requirements

• Authorize maintainer-only commands.
• Use reviewability, queue pressure, duplicate clusters, checks, PR age, and confirmed-miner status.
• Post public-safe summaries only.
• Point private details to authenticated API/control panel.
• Record usage and feedback events.

Public/Private Output Boundaries

Public GitHub output must never include wallets, hotkeys, payout/reward estimates, raw trust scores, public score estimates, private reviewability, private scoreability context, or farming language. Private API/MCP/control-panel surfaces may show authenticated scoreability, blockers, projections, and evidence, but must not claim guaranteed payout outcomes.

Acceptance Criteria

• Maintainer-only commands enforce authorization.
• Output is public-safe if posted publicly.
• Private details require authenticated API/control panel.
• Tests cover maintainer/non-maintainer behavior.

Testing Requirements

• npm run test:ci must pass.
• Global coverage must remain at or above 97% for lines, statements, functions, and branches.
• Aim for 98%+ branch coverage locally.
• Add tests for every new branch, fallback path, sanitizer rule, and regression.
• Add invariant/property-style tests when behavior depends on sorting, gating, scoring, source-upload safety, public/private boundaries, or telemetry privacy.
• MCP/local tooling must prove source contents are not uploaded when local metadata is involved.
• Public GitHub output must be tested against forbidden language: wallet, hotkey, raw trust score, payout, reward estimate, farming, private reviewability, and public score estimate.