Bugfix/jspecify

[jpfinne]

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Summary by cubic

Adds JSpecify nullability to generated Spring path params and expands the jspecify spec with a required multipart upload (JSON response) and a binary download endpoint. Regenerates Java jspecify clients and Spring Boot server samples to add downloadIdGet, the UploadPostDefaultResponse model, and updated docs/tests.

• Bug Fixes

  • Add {{>nullableAnnotation}} to JavaSpring path parameters (@PathVariable) to fix missing nullability in jspecify builds.

• New Features

  • Spec updates: /upload returns JSON UploadPostDefaultResponse; file is required, optional metadata part; new /download/{id} returns application/octet-stream.
  • Regenerated samples for native-jackson3-jspecify, restclient-springBoot4-jackson3-jspecify, resttemplate-springBoot4-jackson3-jspecify, webclient-springBoot4-jackson3-jspecify, and the Spring Boot server (adds DownloadApi and UploadPostDefaultResponse) with updated endpoints, docs, and tests.

^{Written for commit 9389540. Summary will update on new commits.}