Every porcelain-v2 `u` record already carries `mW`, the working-tree mode Git
stat'ed for that row: `000000` means the conflicted path is absent. Reading it
replaces the per-conflict `fs.access`, so the bounded-concurrency resolver, its
`= 8` cap, and the order/error-precedence invariant are unnecessary rather than
cheaper. `access()` stays only as a fallback for a malformed `mW`, so
`parseUnmergedEntry` keeps its signature and neither status-read.ts nor the
relay loop changes.
Also corrects two fixtures that encoded `mW=100644` for a file that does not
exist, which real Git never emits.
Neil
104f44222e