scripts/build-desktop-artifact.test.ts is failing on pylon

[rynfar]

scripts/build-desktop-artifact.test.ts fails on the product branch:

× skips the primary native probe for cross-architecture Windows payloads
  AssertionError: expected true to be false

The test asserts no command runs with ELECTRON_RUN_AS_NODE === "1" when
targetArch differs from the host, and one does.

This is pre-existing, not caused by the current upstream batch

Confirmed by checking out origin/pylon's own copies of both
build-desktop-artifact.ts and its test into a clean tree and running them:
1 failed / 58 passed, the same failure.

So either CI does not run this file, or it has been failing unnoticed. Both are
worth knowing — a red test nobody sees is worse than no test, and this one covers
the Windows packaging probe.

Worth checking together

• Whether CI runs scripts/** tests at all.
• Whether the assertion or the probe drifted — the probe's arch gate
  (if (hostPlatform !== "win32" || hostArchitecture !== input.targetArch) return;)
  is identical to upstream's, so the divergence is likely on the fixture side.

Found during the 2026-08-28 upstream review while verifying #141; recorded in
.agents/upstream-review.md.