Server-side rendering entry for the Lit adapter.

Wraps @lit-labs/ssr to render a single Lit TemplateResult (or a pre-constructed <schema-view> Custom Element template) to an HTML string with Declarative Shadow DOM markup.

Documented limitations

@lit-labs/ssr is currently published under the @lit-labs/* scope: labs status, which the Lit project explicitly flags as "not yet ready for general production use". The schema-components SSR entry inherits these constraints:

1. Labs status. The API surface and output format may change in breaking ways without a major version bump on lit proper. Pin @lit-labs/ssr precisely if you depend on this entry in production.
2. Async component work is not supported. Components that initiate work in connectedCallback and resolve in updateComplete will render at their pre-update state. The built-in <sc-*> elements complete their first render synchronously, so this constraint only bites for consumer- supplied widgets.
3. Light-DOM-only components are not supported. A custom element that overrides createRenderRoot() to return this (rendering into the light DOM rather than a Shadow DOM) will not server-render. All built-in <sc-*> elements use Shadow DOM and so are compatible.
4. @lit/context does not server-render. Any value provided via the context port from lit/contexts.ts is undefined on the server. Consumers must default gracefully.
5. Declarative Shadow DOM support in the consumer's runtime is required for hydration. Modern browsers support it; older targets need the @webcomponents/template-shadowroot polyfill.

Each limitation is documented at the Lit SSR project page: https://lit.dev/docs/ssr/overview/