chore(deps): bump fastify from 5.11.2 to 5.12.0 in /backend

[dependabot]

Bumps fastify from 5.11.2 to 5.12.0.

Release notes

Sourced from fastify's releases.

v5.12.0

What's Changed

• chore(sponsor): add testmu ai by @​Eomm in fastify/fastify#6922
• docs: add per-route logging for Google Cloud Functions by @​slegarraga in fastify/fastify#6907
• test: remove @​sinonjs/fake-timers by @​climba03003 in fastify/fastify#6934
• [Backport 5.x] fix: remove raw response headers by @​github-actions[bot] in fastify/fastify#6939
• [Backport 5.x] test: use process-warning spyWarning for testing by @​github-actions[bot] in fastify/fastify#6945
• [Backport 5.x] feat: add Reply.prototype.mediaType by @​github-actions[bot] in fastify/fastify#6946
• [Backport 5.x] fix(content-type): return undefined for invalid media types by @​github-actions[bot] in fastify/fastify#6947

Full Changelog: fastify/fastify@v5.11.3...v5.12.0

v5.11.3

What's Changed

• fix: clear trailer state when removing all trailers by @​Ram-blip in fastify/fastify#6845
• docs: document percent-decoded route params as untrusted input by @​mcollina in fastify/fastify#6903
• docs(errors): document what the default error handler sends by @​basteez in fastify/fastify#6894
• docs(readme): fix grammar and cjs capitalization by @​minirang in fastify/fastify#6899
• fix: pass null instead of undefined to requestCompleted on success by @​lazerg in fastify/fastify#6837
• docs(encapsulation): clarify nested plugin scopes by @​jean-michelet in fastify/fastify#6893
• chore: Bump fastify/workflows/.github/workflows/lock-threads.yml from 6.0.0 to 7.0.0 by @​dependabot[bot] in fastify/fastify#6916
• chore: Bump fastify/workflows/.github/workflows/nested-quality.yml from 6.0.0 to 7.0.0 by @​dependabot[bot] in fastify/fastify#6917
• fix: recognize constructor-assigned built-in properties as decorator … by @​aquie00t in fastify/fastify#6892
• fix: reset lastIndex before testing global/sticky content-type RegExp parsers by @​zelinewang in fastify/fastify#6846

New Contributors

• @​minirang made their first contribution in fastify/fastify#6899
• @​lazerg made their first contribution in fastify/fastify#6837
• @​zelinewang made their first contribution in fastify/fastify#6846

Full Changelog: fastify/fastify@v5.11.2...v5.11.3

Commits

• 27d1fec Bumped v5.12.0
• 430dd4e fix(content-type): return undefined for invalid media types (#6942) (#6947)
• fd5fe53 feat: add Reply.prototype.mediaType (#6932) (#6946)
• cd04a49 test: use process-warning spyWarning for testing (#6887) (#6945)
• b9e5402 fix: remove raw response headers (#6860) (#6939)
• e1fc825 test: remove @​sinonjs/fake-timers (#6934)
• 2e81c38 docs: add per-route logging for Google Cloud Functions (#6907)
• f87eb61 chore(sponsor): add testmu ai (#6922)
• a22cede Bumped v5.11.3
• 16a74e7 fix: reset lastIndex before testing global/sticky content-type RegExp parsers...
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Summary by cubic

Upgrades fastify in backend from 5.11.2 to 5.12.0 to pick up fixes and clearer content-type handling. Old behavior exposed raw response headers and could return a value for invalid media types; new behavior removes raw response headers, returns undefined for invalid media types, and adds reply.mediaType.

• Verify no code reads raw response headers via reply (e.g., reply.raw); remove any such usage.
• Audit logic that assumes Content-Type parsing always returns a value; handle undefined safely.
• Consider adopting reply.mediaType where we parse Content-Type.
• Note: transitive process-warning updated to 5.1.0; watch for changes in warning output.

^{Written for commit 6886086. Summary will update on new commits.}