base './' emits relative asset URLs; the manifest, the service-worker
registration and sw.js's precache resolve against their own location;
the four hardcoded /image literals turn relative. Verified headless
under a simulated /edentext/ subpath: boots, types, SW scope correct.
Nothing here talks to a server at runtime, so a cached shell is the whole
editor. The worker reads the build's hashed asset names out of the entry
document, which precaches without a build step; the document itself stays
network-first, or it would keep naming the assets of the build it was
cached with. Matching ignores Vary: a precached asset is fetched without
the page's Origin, and a server answering "Vary: Origin" never matches it.
Verified in a headless Chromium with the network cut.
Steffen Becker