fix: correct README multi-path claim, cover repeated --remote-path refusal

Draft
KH
2mo ago
+38-2

Fixes #379.

README documented multi-allowlist scoping as available via "the relayfile CLI directly", but the CLI is also single-root while scoped mount operator surfaces are unavailable. Corrects the README to state that constraint plainly instead of overclaiming, and adds a real regression test proving a repeated `--remote-path` with `--local-layout=scoped` is refused before any network or filesystem side effects (zero server requests, mirror directory never created).

Test plan

  • `go build ./...`
  • `go test ./cmd/relayfile-cli/... -run TestMountRefusesRepeatedRemotePathsWithScopedLayoutBeforeSideEffects -v -count=1`
  • `go test ./cmd/relayfile-cli/... -count=1` (full package suite)