The pricing fetch (loadPricing -> fetchAndCachePricing) runs on every CLI
invocation, and the macOS menubar shells out to the CLI and blocks on its
exit. fetch() had no timeout, so a half-open network after wake-from-sleep
made it hang forever once the 24h pricing cache expired — wedging the
menubar on its loading spinner until relaunch.
Add a shared fetchWithTimeout helper (8s default, AbortSignal.timeout) and
apply it to the two daily-critical-path fetches: pricing (models.ts) and
the currency rate (currency.ts). On timeout the existing catch falls back
to the bundled price snapshot / cached or USD rate.
Reproduced on main (stale cache + black-holed host -> hangs indefinitely);
with the timeout the same scenario aborts in 8s and renders via fallback.
