Experience Builder Custom Widget

Developer Edition custom widget work. The compile version is the constraint everything else hangs on — fix it before writing any widget code.

Establish the version floor first — before any code

1. Read client/package.json in the Dev Edition install for the actual ExB version in use. Never assume a version.
2. Ask which ArcGIS Enterprise version(s) must run this widget.
3. The compile target is the lowest of those Enterprise versions — ExB runs widgets compiled in earlier versions but not newer ones, and the version a widget was compiled in is what matters.
4. Pick the Dev Edition version that uses the same JS SDK version as that target Enterprise — see VERSIONS.md, and re-verify against Esri's release-versions page.

The exbVersion field in manifest.json is declarative and not enforced — hand-editing it downward does not backport a widget. Only compiling in the lower version does.

Check the Node and pnpm gate before running anything

ExB is gated on Node major version, and the gate differs by ExB release. Confirm the Node and recommended pnpm versions for the exact ExB version in use — see VERSIONS.md — before install or start. A wrong Node major fails the toolchain.

Keep the manifest invariants