The 4-worker cap existed only to keep deferred-promise tests inside
Vitest's old 5s default when several workers pay the first dynamic
import of the large store modules at once; a 10s testTimeout absorbs
that without capping throughput. CI keeps 4 workers (4-vCPU runners
already share CPU with vue-tsc/oxlint/oxfmt via pnpm check). Also add
pnpm test:watch for incremental local runs.
t8y2