Summary

Utoopack previously aggregated all regular app entries into one AppEndpoint, which prevented page-level scheduling and made each generated HTML file include assets from every page.

This PR now:

• creates one AppEndpoint per regular app entry while sharing the project module/runtime contexts;
• builds independent Client and plain server.entry work concurrently; server.function still intentionally scans all Client graphs to discover server references;
• keeps copy assets and the memoized Server output reachable from every endpoint, so writing any page independently preserves shared outputs without rebuilding them;
• generates entry HTML from its owning endpoint(s), groups multiple module scripts that target the same HTML file, and keeps global HTML asset order deterministic;
• serializes/coalesces HTML writes so concurrent HMR updates cannot overwrite newer asset sets;
• reduces dev NAPI subscriptions from 2N to N for browser-only/Node targets, and to N+1 for browser apps with shared Server output;
• fails fast when the endpoint/config cardinality contract diverges;
• scopes development stats chunk lists to their owning endpoint instead of attaching every page bootstrap to every stats entrypoint.

Observable API note: entrypoints.apps now contains one endpoint per ordinary app entry instead of one aggregate endpoint. The endpoint order remains the filtered config entry order. A configured global HTML file still needs the union of all endpoint assets, so regenerating that single global file remains O(N), but concurrent updates are coalesced into one ordered writer.

Paired clean-build benchmarks with persistent cache disabled:

For the 32-page HTML fixture, each page now includes one owning entry script instead of all 32 entry scripts. A real 19-page EVJS MPA likewise dropped from 19 page entry scripts per HTML file to 1; all 19 pages returned HTTP 200, and page HMR remained scoped after rebuild.

Test Plan

• cargo fmt --check
• cargo clippy --all-targets -- -D warnings --no-deps
• UPDATE=1 cargo test -p pack-tests --test snapshot multi_page_shared_outputs -- --ignored --nocapture
  • verifies two app endpoints;
  • writes each endpoint independently;
  • verifies each contains copy output and the shared Server bundle;
  • verifies the shared Server bundle contains a Server Function discovered from the second page.
• npm test --workspace @utoo/pack (55 passed)
  • covers HTML ordering/grouping/concurrent writes, browser/Node watcher counts, and per-entrypoint dev stats ownership.
• npm run build:js --workspace @utoo/pack
• npx biome ci
• npx tsc -p packages/pack/tsconfig.json --noEmit
• Paired release-local benchmark for 20-page production with copy + server.entry, persistent cache disabled.