Add scalafmt (plugin) to scala-akka client generator

[wing328]

based on #23296 with updated tests

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• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• 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.
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---

Summary by cubic

Adds Scalafmt support to the Scala Akka client generator so generated projects have consistent, auto-formatting out of the box. Also updates website dependencies to @docusaurus/* v3.9.2.

• New Features

  • Generator now emits project/plugins.sbt with sbt-scalafmt 2.5.6 and a .scalafmt.conf (Scala 2.13 dialect, opinionated rules).
  • Samples updated to include these files; tests adjusted to expect 18 generated files.

• Dependencies

  • Bumped @docusaurus/core, @docusaurus/plugin-google-analytics, @docusaurus/preset-classic, and @docusaurus/utils to ^3.9.2; refreshed yarn.lock.

^{Written for commit 7b8a829. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 9 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="website/package.json">

<violation number="1" location="website/package.json:15">
P1: Upgrading to Docusaurus v3 without also upgrading React/ReactDOM and prism-react-renderer introduces dependency incompatibilities that can break install/build.</violation>
</file>

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

[cubic-dev-ai]

P1: Upgrading to Docusaurus v3 without also upgrading React/ReactDOM and prism-react-renderer introduces dependency incompatibilities that can break install/build.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At website/package.json, line 15:

<comment>Upgrading to Docusaurus v3 without also upgrading React/ReactDOM and prism-react-renderer introduces dependency incompatibilities that can break install/build.</comment>

<file context>
@@ -12,10 +12,10 @@
-    "@docusaurus/plugin-google-analytics": "^2.3.1",
-    "@docusaurus/preset-classic": "^2.3.1",
-    "@docusaurus/utils": "^2.3.1",
+    "@docusaurus/core": "^3.9.2",
+    "@docusaurus/plugin-google-analytics": "^3.9.2",
+    "@docusaurus/preset-classic": "^3.9.2",
</file context>