[KOTLIN-SPRING/KOTLIN-CLIENT] BUG - fix json deserialization when kotlin attribute name differs from json attribute name

[Picazsoo]

When using e.g. nameMappings or just depending on the generator's substitution logic to safely escape json properties names for kotlin parameters, the currently generated @get:JsonProperty("...") is not sufficient to allow safe deserialization as it only handles serialization via the getter association. Hence I added also @param:JsonProperty("...") to also allow proper deserialization.

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Summary by cubic

Fixes Jackson deserialization in generated Kotlin models by adding @param:JsonProperty so constructor params bind to the original JSON keys. Models now deserialize correctly when fields are renamed via name mappings or auto-renamed (e.g., digit-starting names).

• Bug Fixes
  • Add @param:JsonProperty next to @get:JsonProperty in kotlin-client and kotlin-spring templates for required and optional vars.
  • Use the original JSON key for the param annotation to honor nameMappings and backtick-escaped identifiers.
  • Add tests for mapped and digit-starting fields (client and spring), include a small OAS spec, and stabilize a spring test by extending its lookup window.
  • Regenerate Kotlin samples to include the new annotations.

^{Written for commit d1976d7. Summary will update on new commits.}

[cubic-dev-ai]

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