feat: implement attestation history timeline

[xx7412421-cloud]

Closes #578.

Summary

• replace the placeholder AttestationHistory component with an API-backed timeline filtered by commitment id
• render compliance scores, pass/violation badges, attestor/timestamp details, and a Recharts trend panel
• add loading, empty, and retryable error states plus RTL coverage for edge cases

Validation

• npm exec -- vitest run src/components/tests/AttestationHistory.test.tsx
• npm exec -- eslint src/components/AttestationHistory.tsx src/components/tests/AttestationHistory.test.tsx
• npm exec -- prettier --check src/components/AttestationHistory.tsx src/components/tests/AttestationHistory.test.tsx
• git diff --check

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[1nonlypiece]

thanks for the attestation-history timeline — i can't take it as-is though, because #578 isn't assigned to you and we need the PR author claimed on the issue first. closing as invalid for now; claim #578 on the board and raise it again. https://discord.gg/WV7tdYkJk