Build macOS app before reusable release

[vuon9]

Summary

• move the Wails/macOS app build into DevToolbox's release workflow
• upload the built .app as a short-lived artifact
• call the generic gh-workflows macos-release.yml reusable workflow for Developer ID signing, notarization, DMG packaging, and release artifact upload

Verification

• YAML parse: ok
• git diff --check: exit 0
• workflow_dispatch succeeded: https://github.com/vuon9/devtoolbox/actions/runs/27663369771
• Successful artifacts: devtoolbox-macos-app-27663369771, devtoolbox-macos-release-27663369771

Merge note

• This PR currently references vuon9/gh-workflows@wails-macos-release-workable so the split can be verified before gh-workflows PR Fix encode/decode tools and merge all possible tools into one #4 merges. After Fix encode/decode tools and merge all possible tools into one #4 lands, update the ref to the released tag or main before merging this PR.

[github-actions]

Package	Line Rate	Health
devtoolbox/internal/barcode	93%	✔
devtoolbox/internal/codeformatter	80%	➖
devtoolbox/internal/converter	65%	➖
devtoolbox/internal/datagenerator	81%	✔
devtoolbox/internal/datetimeconverter	75%	➖
devtoolbox/internal/jwt	47%	❌
devtoolbox/internal/numberconverter	98%	✔
devtoolbox/internal/settings	0%	❌
devtoolbox/internal/themes	0%	❌
Summary	70% (3726 / 5294)	➖

Minimum allowed line rate is 60%