Consult the module map before fetching runtime module script roots while
preserving script-element Service Worker filtering and integrity checks.
Keep shared fetches alive across document.open so imports in the retained
realm settle without reviving retired script elements or their events.
Start connected main-document modulepreloads during mutation commit using the
same module-map reservation and scheduling path as parser preloads. Route child
links through the existing Document/realm-owned modulepreload queue instead of
leaving their start requests in the main lifecycle accumulator.
Cover post-load JavaScript/JSON/CSS/text preloads, import reuse, asynchronous
load/error delivery, CORS and integrity failures, per-Window module maps, and
queued child starts retired by document.open.