Adds /__wrnexus/islands.js (the bootstrap) and the /__wrnexus/island/
prefix (mount runtime, island bundles, shared chunks) to all three
serving paths.
Dev reuses the browserArtifactPaths registry pattern from pipeline.ts.
Prod mirrors the clientModulesDir handler, including its filename
allowlist, so island names cannot escape the output directory.
The bootstrap is inert without a data-wrn-island marker, so island-free
pages still download nothing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Mounts markers with client:only/load/visible/idle, and disposes roots on
route change so React roots, detached DOM, and store subscriptions do
not leak across client-side navigation.
Bundle load failures and malformed props JSON degrade to a warning and
leave the server markup intact rather than taking down the page.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
ClintchizandClaude Opus 5