Summary

HIGH-severity code-quality findings (runtime-breaking bugs) detected in this repo.

Affected files

Presigned-PUT content-type mismatch breaks SigV4 — 403 on upload (backend/server.js:95)

Why it matters

These cause incorrect results or crashes, undermining the repo as a reference implementation.

Suggested fix

Per item: add error handling, input validation, and fix the specific issues listed above.

Acceptance criteria

• Each item fixed and re-scanned clean by /health-check code-review

Filed by quality-keeper (2026-06-19). Migrated from backblaze-labs/demand-side-ai#376.