One-shot prettier pass so the new format:check gate starts from a clean
baseline. Formatting only — no behaviour change. Generator-owned and
vendored artifacts stay untouched via .prettierignore.
`public/sw.js` carries a `|| "..."` fallback literal used for `CACHE_VERSION`
when `importScripts('/sw-version.js')` is unavailable. The literal had drifted
to `v1.4.43`, four-plus minors behind `package.json`; in any environment where
the generated file is missing this keyed every cache to the stale version and
turned the activate-step eviction into a no-op — the exact bug the generator
was written to kill.
Extend the prebuild generator to rewrite the fallback literal in `sw.js` to the
current `package.json` version on every build, anchored on a
`/* @sw-version-fallback */` marker (the build fails loudly if the marker is
gone). The literal and the generated `sw-version.js` can no longer diverge.
The SW test now reads the fallback straight from the source so it tracks the
literal instead of hard-coding it.
Marc-André Bombeck