feat: surface run completion governance

[xiaojiou176]

Summary

• fetch persisted planning_worker_prompt_contracts.json when a run manifest advertises the artifact
• surface a read-only completion governance summary on Run Detail for worker prompt contracts, on-incomplete/on-blocked rules, and DoD checks
• extend the Run Detail test harness to mock the planning-contract artifact path and verify the new operator summary

Why

• worker_prompt_contract is already a persisted run-local artifact on main, but Run Detail only showed existence-level artifact labels
• this PR turns the persisted governance contract into an operator-readable summary without changing execution authority
• task_contract remains the only execution authority; the new panel stays explicitly advisory

Verification

• pnpm --dir apps/dashboard exec vitest run tests/rundetail_core.suite.tsx tests/api_wrappers.suite.ts
• pnpm --dir apps/dashboard exec tsc -p tsconfig.typecheck.json --noEmit
• npm run truth:triage (repo-side green; external truth still red only on the known Docker/platform upstream records: ci-core-image.json and ui-audit-playwright.json)

Review notes

• local designer blocker-only review: APPROVE
• local integration review verified the summary stays below role-binding authority and above raw artifact inventory
• explorer evidence on main showed continuation_policy was already persisted into worker prompt contracts but not yet operator-readable on Run Detail