Fix/292 ssr claim receipt

[karanjakevin39-collab]

• Convert claim-receipt page from a client-fetched (useEffect + mock
  data) page to an async Server Component that fetches
  /api/v1/claims/{id}/receipt during SSR
• Mark the route force-dynamic and fetch with cache: 'no-store' so the
  backend's own Cache-Control header (private, must-revalidate, [HIGH] Hash all legacy plaintext API keys and drop plaintext column #32)
  governs revalidation instead of Next's data cache
• Extract the interactive Back button into its own client component
• Widen ClaimReceiptData status union to include 'cancelled', matching
  the backend DTO
• Add a mock handler for /api/v1/claims/:id/receipt so SSR works
  locally with NEXT_PUBLIC_USE_MOCKS=true
• Add Playwright + an E2E test asserting FCP < 1s under a throttled
  Slow 3G / 4x CPU profile

Closes #292

[kilodesodiq-arch]

👋 Thanks for the contribution! This PR contains code/test changes and CI workflows were never auto-triggered (a GitHub Actions safety requirement for cross-repo forks). To unblock this for merging, a maintainer needs to either:\n\n1. Manually click 'Approve and run workflows' on this PR's Actions tab via the GitHub UI, or\n2. Approve the pending CI on the PR checks page.\n\nOnce the CI checks pass, this can be merged. 🚀

[karanjakevin39-collab]

please merge fixed the failing checks