fix(kotlin-client): emit parameter table header before first parameter

[raunak2007]

Problem

Follow-up to #24742. That PR fixed kotlin-client/api_doc.mustache, but the jvm-retrofit2 library ships its own copy, which still emits the parameter table header inside {{#-last}}. For operations with two or more parameters the header lands before the final parameter and every preceding row falls outside the table.

Visible on master today — samples/client/petstore/kotlin-jvm-retrofit2-coroutines/docs/PetApi.md (deletePet): the petId row sits above the header.

Fix

{{#-last}} → {{#-first}} on the header block, matching #24742.

Samples

Regenerated bin/configs/kotlin*.yaml. 21 files, 68 insertions / 68 deletions — every change is a parameter row moving below the header. No non-doc output affected.

I checked every api_doc.mustache in the tree structurally; this was the last one with the header nested inside the row loop.

PR checklist

• Read the contribution guidelines.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

  (For Windows users, please run the script in WSL)
  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
  IMPORTANT: Do NOT purge/delete any folders/files (e.g. tests) when regenerating the samples as manually written tests may be removed.
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

---

Summary by cubic

Fixes Kotlin jvm-retrofit2 API docs to emit the parameter table header before the first parameter. Previously the header rendered on the last parameter, leaving earlier rows outside the table; now the header renders on the first parameter and all rows appear inside the table.

Review notes

• Updates modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-retrofit2/api_doc.mustache: switch {{#-last}} to {{#-first}} for the header block.
• Regenerates samples via bin/configs/kotlin*.yaml; diffs move parameter rows below the header (e.g., samples/client/petstore/kotlin-jvm-retrofit2-coroutines/docs/PetApi.md).
• Documentation-only change; no generator or runtime behavior changes. No migration actions.

^{Written for commit 09c6500. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 21 files

_{Re-trigger cubic}