amicode-vaults.test.ts hardcodes POSIX path separators — unit (windows) red

[jack-champagne]

packages/opencode/test/server/amicode-vaults.test.ts asserts on literal /-separated paths, so it fails on Windows where the resolver correctly returns \-separated ones.

From the unit (windows) job on #2:

amicode-vaults.test.ts:14
  [
    "/x/bin/av",
-   "/y/ops/scripts/amico-vault",
-   "/home/u/.amico/ops/scripts/amico-vault",
+   "\y\ops\scripts\amico-vault",
+   "\home\u\.amico\ops\scripts\amico-vault",
  ]
(fail) candidates > resolution order: AMICO_VAULT_BIN, then AMICO_OPS, then the canonical ops path

amicode-vaults.test.ts:21
(fail) candidates > unset env vars are skipped; canonical path is always last

This is a test bug, not a product bug — the resolver is doing the right thing per-platform; the assertion isn't platform-agnostic.

Pre-existing. It is not caused by #2. It was invisible until now only because the fork's workflows requested blacksmith-4vcpu-* runners that this org has none of, so no job ever ran. #2 moves CI to GitHub-hosted runners and therefore makes this failure visible for the first time.

Fix: normalise with path.join / path.sep in the expectations, or skip the case on process.platform === "win32".

Agreed with @jack-champagne to land #2 with this check red rather than widen its scope.