portal: link PCS claims from assurance action nodes

[fraware]

Why this helps

Assurance action pages already carry pcs_claim_id on nodes (AssuranceNode in portal/lib/assuranceTypes.ts), and the portal has /pcs/claims/[claimId]. The action UI never surfaces those IDs as links, so readers cannot jump from an action chain to the portable PCS evidence layer. Small UX polish that makes the assurance/PCS boundary obvious for first-time explorers.

Scope

On /assurance/actions/[actionId], when a node (or chronology entry) has a non-null pcs_claim_id, render a link to /pcs/claims/<id>. Keep existing non-claim copy. Prefer reading only from portal/.generated/assurance-export.json (no new fetch paths).

Suggested starting points

• portal/components/assurance/AssuranceActionPage.tsx (NodeList, chronology, authority list)
• portal/lib/assuranceTypes.ts (pcs_claim_id on AssuranceNode)
• portal/app/assurance/actions/[actionId]/page.tsx
• portal/app/pcs/claims/[claimId]/ (target route)
• pipeline/src/sm_pipeline/assurance/export/__init__.py (confirm export already includes pcs_claim_id when present)
• Optional smoke: portal/scripts/verify-assurance-export.mjs

Acceptance criteria

• Nodes with pcs_claim_id show a navigable link to /pcs/claims/<pcs_claim_id>
• Nodes without pcs_claim_id behave as today (no broken empty links)
• Non-claim disclaimer text on the action page remains
• Portal lint/build still pass; no invented claim digests or status rewrites
• Brief note in PR description of how to verify with local portal + exported data

Non-goals

• Importing or validating nested PCS bundles (separate issue)
• New assurance export schema fields beyond what export already emits
• Redesigning the full /assurance IA or adding a metrics dashboard

How to test

uv run --project pipeline sm export-assurance-portal-data
pnpm --dir portal lint
pnpm --dir portal build
pnpm --dir portal exec node scripts/verify-assurance-export.mjs
just portal
# Open /assurance/actions/<id> for an action whose export nodes include pcs_claim_id
# (may require a fixture/corpus chain that sets pcs_claim_id; if pilots use mode=none,
# add a minimal test fixture or use an existing PCS-linked node in a local export)

If you need a fixture with pcs_claim_id populated and none exists yet, keep the fixture change minimal and document it in the PR.