ci(apps): rename the signing environment to native-macos

[eliahilse]

TL;DR:

Summary:

• renames the deployment environment the signing job declares from apple-signing to native-macos, and updates the reference in apps/native-viewer/macos/README.md
• native-* groups the native apps as one family, so a future Linux pipeline sits alongside as native-linux rather than scattering by platform

Merge only after the environment exists under the new name. Otherwise the signing job resolves an environment with no secrets and quietly produces an unsigned build instead of failing. Either rename apple-signing in place from Settings → Environments, which preserves the secrets, or create native-macos and re-add the six secrets first.

Test plan:

• the environment native-macos exists and holds all six Apple secrets
• run the workflow manually and confirm the artifact name has no -unsigned suffix
• delete the now-unused apple-signing environment

[openooxml-bot]

All contributors have signed the CLA — thank you! ✍️ ✅

_{Posted by the CLA bot.}

[greptile-apps]

Greptile Summary

Renames the macOS signing environment from apple-signing to macos-native in the workflow and its setup documentation.

• Updates the signing job’s GitHub environment declaration.
• Updates the README’s environment-gate and secret-configuration instructions.

Confidence Score: 4/5

The PR appears safe to merge once its explicitly documented environment prerequisite is satisfied; only a minor documentation grammar issue remains.

The workflow and documentation consistently use the new environment name, while the sole accepted issue is an incorrect article in the updated README.

Files Needing Attention: apps/native-viewer/macos/README.md

Important Files Changed

Filename	Overview
.github/workflows/macos-app.yml	Renames the signing job environment consistently; the externally managed environment migration is explicitly documented as a merge prerequisite.
apps/native-viewer/macos/README.md	Updates both environment references but introduces the grammatical phrase “an macos-native environment”.

_{Reviews (1): Last reviewed commit: f798f11 | Re-trigger Greptile}

[greptile-apps]

Incorrect article before environment name

The updated instruction uses an before macos-native, leaving a grammatical error in the setup documentation; it should read “Create a macos-native environment”.

Suggested change

	Create an `macos-native` environment with required reviewers, then create
	Create a `macos-native` environment with required reviewers, then create

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!