fix: keep $ServerOnly templates in client HMR transforms

[brenelz]

Fixes #308.

The gap

babel-plugin-jsx-dom-expressions@0.40.10 added omitServerOnlyTemplates and defaults it to true. With hydratable: true, an element marked $ServerOnly then compiles to getNextElement() with no template argument. That is fine during hydration, but getNextElement falls back to template() whenever it is not hydrating, so re-creating the element on the client throws TypeError: template is not a function.

Solid Refresh does exactly that on every hot update: it disposes the old root and re-runs the component outside of hydration. So with solid({ ssr: true }) in dev, the first edit of any file containing a $ServerOnly element throws and leaves stale DOM (repro: https://github.com/birkskyum/repro-solid-server-only-hmr, downstream report solidjs/solid-start#1930).

Fix

The plugin already knows when HMR is active (needHmr) and whether a transform targets the client. For client transforms while HMR is active it now passes omitServerOnlyTemplates: false to babel-preset-solid, so the template stays registered and Solid Refresh can re-create the element. The hydration path is unchanged, since getNextElement still prefers the hydration registry.

• Server transforms and production builds keep omitting the template, so no $ServerOnly markup ships to production clients.
• An explicit solid.omitServerOnlyTemplates setting still takes precedence.
• Older compiler versions that do not know the option ignore it.

Also adds omitServerOnlyTemplates to the Options['solid'] type, a README note, and a changeset.

Verification

Built the plugin and ran its transform hook on the repro's App.tsx against babel-preset-solid@1.9.15 / babel-plugin-jsx-dom-expressions@0.40.10:

Scenario	Template registered
ssr: true, dev server, client transform	yes, getNextElement(_tmpl$)
ssr: true, dev server, server transform	n/a, ssr(...) output
ssr: true, dev server, hot: false	no, getNextElement()
ssr: true, dev server, solid: { omitServerOnlyTemplates: true }	no, getNextElement()
ssr: true, production build, client transform	no, getNextElement()
solid: { hydratable: true } without ssr, dev server	yes, getNextElement(_tmpl$)

tsc --emitDeclarationOnly and prettier --check pass on the changed files.

🤖 Generated with Claude Code

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🦋 Changeset detected

Latest commit: b50c064

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
vite-plugin-solid	Patch

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commit: b50c064