- Fix for two Fastify security advisories (GHSA‑w2qp‑rph6‑63g4 and GHSA‑3m5p‑2c4r‑xxw2).
- Backported bug fixes: corrected reply.mediaType handling, ensured preClose hook runs once per instance, fixed canonical route URL for hidden‑prefix slash routes, and allowed backport in PR titles.
- Minor CI and test updates.
v5.12.1
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Added per‑route logging for Google Cloud Functions and introduced `Reply.prototype.mediaType` for easier content‑type handling.
Fixed trailer state clearing when removing all trailers and corrected requestCompleted handling to use null instead of undefined.
Minor updates and bug fixes