Docs claim Swift build produces a DMG, but no script in-tree does

[cfbraun]

Problem

packaging/README.md (Installation section) currently states:

1. Open the DMG produced by the Swift build.

But after #1355 (which removed packaging/build.py's create_dmg / sign_app / bundle pipeline), nothing in the repo actually creates a .dmg:

• apps/omlx-mac/Scripts/build.sh release produces oMLX.app only — no DMG step (grep -rn "hdiutil\|create-dmg\|\\.dmg" apps/omlx-mac/Scripts/ returns nothing)
• No CI workflow under .github/workflows/ creates one either
• The Swift updater (AppUpdater.swift) consumes DMGs from GitHub Releases but doesn't make them

The DMGs at https://github.com/jundot/omlx/releases presumably come from a maintainer-side script that isn't in the public tree.

Impact

Developers building locally from packaging/README.md end up with build/Stage/oMLX.app but no DMG, contradicting the install instructions one section down. The drop-Swift-replaces-PyObjC migration removed the DMG-producing code without replacing it or updating the docs.

Suggested fixes

Either:

1. Add an opt-in DMG step to apps/omlx-mac/Scripts/build.sh — e.g. a --dmg flag that wraps $STAGED_APP with hdiutil create -volname oMLX -srcfolder ... -format UDZO. Keeps the default flow unchanged for the auto-rebuild / Xcode-run loop, but gives local builders a documented way to produce a DMG matching the Releases shape. Update packaging/README.md to reflect the new flag.

2. Or remove the DMG claim from packaging/README.md and document that DMGs only come from official releases.

I'll open a PR doing (1) since it lines up with the README's existing wording. Open to either resolution.

[jundot]

Thanks for the PR! I had this on my list as a follow-up commit, but you got there first. I'll take a look at #1457 soon.

[cfbraun]

Reconsidered the two suggested fixes. Going with (2) — fix the docs, don't add a DMG-creation script.

Rationale: a developer who built oMLX.app locally already has the install artifact they need (drag-to-Applications is the standard macOS pattern). DMGs are a distribution wrapper for shipping to end-users — a concern that's already handled by whatever off-tree pipeline produces the Releases DMGs. Adding hdiutil to build.sh would be ~30 lines of maintenance surface for nearly-zero local-developer value.

PR #1457 collapsed to the docs-only fix.

[cfbraun]

@jundot heads-up — #1457 auto-closed when I renamed the branch (pr/swift-bundle-dmg → pr/docs-packaging-dmg-claim to match the docs-only scope). Same content lives in #1458 now. GitHub's branch-rename API doesn't retarget cross-fork PRs, so the close was unavoidable. Pointing #1458 at this issue so it closes on merge.