Add scalafmt (plugin) to scala-sttp4 client

[wing328]

cc @clasnake (2017/07), @shijinkui (2018/01), @ramzimaalej (2018/03), @chameleon82 (2020/03), @Bouillie (2020/04) @Fish86 (2023/06)

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---

Summary by cubic

Adds Scalafmt to the Scala STTP v4 client generator to ensure consistent formatting. The generator now outputs a .scalafmt.conf and enables the sbt-scalafmt plugin.

• New Features

  • Generates .scalafmt.conf (Scalafmt 3.10.6, Scala 2.13 dialect).
  • Adds project/plugins.sbt with org.scalameta sbt-scalafmt 2.5.6.
  • Updates Scala STTP v4 samples to include these files.

• Refactors

  • Stops generating DateSerializers.scala.

^{Written for commit 5579d82. Summary will update on new commits.}

[cubic-dev-ai]

2 issues found across 6 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="modules/openapi-generator/src/main/resources/scala-sttp4/scalafmt.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/scala-sttp4/scalafmt.mustache:4">
P1: `project.git = true` makes formatting depend on Git-tracked files, so a freshly generated client outside a Git repo won't be formatted.</violation>

<violation number="2" location="modules/openapi-generator/src/main/resources/scala-sttp4/scalafmt.mustache:63">
P2: This failure message tells users to run `./scalafmt`, but scala-sttp4 clients don't generate that script.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}