Docs: clarify Web packaging requirements in developer-setup vs supported-platforms #711

Forum Post: https://community.cesium.com/t/adding-webgl-specific-packaging-requirements-to-developer-setup-md/46720
Category: Cesium for Unity
Reported by: @hv_nico (community forum)
Cesium/Unity versions mentioned: Unity 6+ for Web, current docs still recommend Unity 2022.3 for developer setup

Problem

Documentation~/developer-setup.md currently reads as a general prerequisite list and still recommends Unity 2022.3 LTS, while Web support requires Unity 6+ and additional Web-specific setup documented elsewhere. This creates confusion for users trying to package for Web.

The forum report also points out that WebGL native build configuration uses -G Ninja in Source/Editor/CompileCesiumForUnityNative.cs, so tooling expectations are not obvious from contributor docs.

Proposed docs updates

1. In developer-setup.md, explicitly scope Unity 2022.3 guidance to general contributor/editor workflows.
2. Add a “Web packaging prerequisites” subsection that links to supported-platforms.md#web.
3. Explicitly call out Unity 6+ for Web target builds.
4. Add a note about Web build tooling expectations (including Ninja-related behavior and where to troubleshoot).
5. Add cross-links between developer-setup.md and supported-platforms.md#web to avoid drift.

Source references

• https://community.cesium.com/t/adding-webgl-specific-packaging-requirements-to-developer-setup-md/46720
• https://cesium.com/learn/cesium-unity/ref-doc/developer-setup.html
• https://cesium.com/learn/cesium-unity/ref-doc/supported-platforms.html#web
• https://github.com/CesiumGS/cesium-unity/blob/main/Source/Editor/CompileCesiumForUnityNative.cs#L619-L626

• cesium-unity/.github/workflows/build.yml

  Lines 490 to 492 in 17ba7d5

  	# We must use Unity 6+ because the Emscripten version in older releases is too old.
  	Start-Process -FilePath "C:/Program Files/Unity Hub/Unity Hub.exe" -Args "-- --headless install --version 6000.0.62f1 --changeset f99f05b3e950" -Wait
  	Start-Process -FilePath "C:/Program Files/Unity Hub/Unity Hub.exe" -Args "-- --headless install-modules --version 6000.0.62f1 --changeset f99f05b3e950 --module webgl" -Wait

• https://cesium.com/blog/2026/03/16/introducing-cesium-for-unity-web/