feat(history): persist exact reruns

[JustinPerea]

Summary

• persist the newest 100 Canvas graph, node, and selection runs in a versioned browser store
• capture the exact normalized execution graph plus the original single-node target
• add Rerun, Retry failed, and persistent clear-history actions
• replay with a new run ID while preserving source lineage and ignoring stale source completions
• recover corrupted storage safely and convert orphaned running records to cancelled on reload
• repair and strengthen the utility-node browser smoke test with tracked fixtures, real store execution, saved-snapshot rerun, and reload persistence proof

Validation

• backend: 1,197 passed with the same two existing AsyncMock warnings
• frontend: 408 passed across 53 files
• lint, TypeScript, and production build passed
• 142 node contracts passed
• generated model reference is current
• utility-node browser smoke passed, including 17-node/14-edge exact rerun and reload persistence
• npm audit: zero vulnerabilities
• git diff check and staged credential scans passed

The production build retains the existing lottie-web direct-eval and large-chunk warnings. No paid provider call ran. User-owned test.html and test_files remain untracked and untouched.