docs(launch): create repo-owner onboarding checklist

[JSONbored]

Parent phase: #238
Parent roadmap: #127

Problem

Repo owners need a checklist for whether their repo is ready to accept Gittensory-driven contribution traffic and what maintenance tradeoffs they are opting into.

Acceptance criteria

• Checklist covers repo policy, labels, issue quality, validation commands, maintainer capacity, contribution lanes, and public/private boundaries.
• Checklist includes honest tradeoffs around maintainer burden and low-quality PR pressure.
• Checklist links to the owner workflow and onboarding pack issues.

Validation expected

• Docs build/lint passes if applicable.
• Checklist is specific enough to use during repo registration review.

Public-output safety criteria

• Public text is sanitized before reaching GitHub comments, issue bodies, PR bodies, extension-visible public panels, or copied public snippets.
• Tests cover forbidden wallet/hotkey, reward-estimate, trust-score, public-score-prediction, private-reviewability, private-scoreability, and farming-language leakage.

Cross-cutting acceptance criteria

• Preserve the repo quality gate: npm run test:ci, 97%+ global coverage, and the local branch coverage target for touched code.
• Keep public/private boundaries explicit. Public GitHub output must not expose wallets, hotkeys, reward estimates, raw trust scores, public score predictions, private reviewability, private scoreability context, or farming language.
• Add/update focused tests for the changed behavior instead of relying on green checks alone.