Add escalation judge runx skill

[fengyangxxx]

Summary

• Add first-party runx skill \escalation-judge`n- Route high-severity churn/support signals to a named internal lane while refusing missing policy or undeclared lanes
• Record escalation decisions through data-store append/readback receipts; no external Slack/customer side effect

Verification

• node scripts/generate-official-lock.mjs
• pnpm build
• pnpm exec tsx packages/cli/src/index.ts doctor --json
• docker run --rm -v $PWD:/repo -w /repo node:24-bookworm node scripts/check-authoring-package-contract.mjs
• npx -y @runxhq/cli@0.6.14 harness ./skills/escalation-judge --json
• npx -y @runxhq/cli@0.6.14 skill ./skills/escalation-judge --json with dogfood fixture
• npx -y @runxhq/cli@0.6.14 verify dogfood receipt tree --json