Track build-time wiring for PPR pregenerated concrete-path registry

PR #1716 injects pregenerated concrete paths into `dist/server/index.js` during `vinext deploy` so the PPR fallback-shell guard can avoid serving placeholder shell HTML for known pregenerated routes whose exact cache entry is absent.

This works for the `vinext deploy` path, and PR #1716 adds coverage that the injected Worker entry hydrates the registry at module init.

Follow-up: decide whether this registry population should move into normal build/prerender finalization, or whether direct publication of build artifacts with Wrangler should be explicitly documented as unsupported for this feature.

Questions to resolve:

- Should `vinext build` artifacts always include the concrete-path registry?
- Is `vinext deploy` the only supported publication path for cacheComponents fallback-shell serving?
- Do we need an E2E/direct-Wrangler test proving supported publication paths populate `getRenderedConcreteUrlPathsForRoute(route.pattern)`?

Refs #1359
Refs #1716