Intel Mac (x64) builds: an unsigned local build works; should there be an official one?

[HuoDx]

Problem

The macOS release is Apple Silicon only (README, electron-builder.yml
mac.target), so Intel Mac users have no download. npm run desktop:dist
also can't help them, because it's tied to arm64 and to the maintainer's
signing and notarization setup.

What I tried

On my Intel Mac (x86_64, macOS 26.3, Xcode 26.1.1, Node 26.13.0), at v0.5.0
(713377f), I ran the steps in docs/desktop-release.md → Build pipeline.
I made no source changes.

Step	Result
npm ci	ok
Native renderer tests under Electron's Node	28/28 pass
npm run build	ok
node scripts/smoke-provider-runtime.mjs	pass
node scripts/build-server.mjs	ok
node scripts/smoke-server.mjs --electron	pass

Packaging (unsigned, no notarization):

CSC_IDENTITY_AUTO_DISCOVERY=false npx electron-builder --mac dmg zip --x64 \
  --publish never -c.mac.notarize=false

This produced LearnHarness-0.5.0.dmg, LearnHarness-0.5.0-mac.zip, their
blockmaps, and latest-mac.yml. The app executable and its packaged native
modules (resvg-js-darwin-x64, @napi-rs/canvas-darwin-x64,
sharp-darwin-x64) are all x86_64.

Two things I ran into:

• --mac --x64 alone also builds arm64. I saw electron-builder package
  the x64 targets and then start an arm64 package in dist/mac-arm64. My
  reading of app-builder-lib's computeArchToTargetNamesMap is that the
  config's arch: [arm64] is added on top of the CLI arch unless the CLI
  names the targets. Naming them (--mac dmg zip --x64) builds x64 only.
• x64 artifacts have no arch in their filenames (LearnHarness-0.5.0.dmg,
  versus -arm64.dmg), because electron-builder leaves out the default arch.

Not tested

• Opening and using the packaged app
• The release workflow's post-package checks (packaged provider and demo
  runtime)
• Signing, notarization, and auto-update

Questions

1. Is Intel Mac support something you want, and if so, at what level?
   • (a) docs only: an unsigned local build path, or
   • (b) official signed releases?
2. For (b), where should it build? Native modules are built for the build
   machine's architecture, and the icon needs macOS 26 + Xcode 26 actool.
   The release workflow notes that Xcode 26's asset compiler crashes on
   macOS 15. I'm not sure GitHub offers an Intel runner on macOS 26.
   Cross-building on the arm64 runner would need x64 native packages.
3. For (b), scripts/verify-release.ts (11 assets, arm64-only Mac targets),
   the artifactName for Mac, and latest-mac.yml with two architectures
   would all need to change. Does that fit your release plans?

If (a) sounds useful, I can open a docs-only PR adding an "Intel Mac (x64),
unsigned local build" section to docs/desktop-release.md.