feat(download): point at the live Mac App Store listing (#241)

[TemujinCalidius]

The FediHome macOS app is out of review and live on the Mac App Store 🎉 — so the download surface should link to it instead of showing "coming soon".

What changed

The /download page already rendered the App Store button whenever macosAppStoreUrl was set, and fell back to a "coming soon" placeholder when empty. It was empty only because the listing didn't exist yet.

So this gives it a real default, exactly the way macosReleaseUrl already defaults to the app's GitHub releases:

macosAppStoreUrl:
  process.env.DOWNLOAD_MACOS_APP_STORE_URL ||
  "https://apps.apple.com/app/fedihome/id6790605091",

There is one FediHome macOS app, and every instance that enables the download page should point at it. macosEnabled stays false by default, so the blast radius is only opted-in instances — i.e. the demo.

On the URL

Region-neutral on purpose — dropped the /au/ and the legacy ?mt=12 from the raw listing link. This default ships worldwide, so a country-locked URL would land every visitor in one country's storefront first; the region-neutral form lets Apple redirect each person to their own store, resolving to the same app.

Copy cleanup

The "coming soon / until the listing is approved" wording is now stale, so it's updated everywhere it appeared: the page comment, .env.example, and docs/configuration.md. The placeholder branch stays in the page — harmless — for anyone who explicitly clears the URL.

Verification

Check	Result
npx tsc --noEmit	clean
npx eslint .	0 errors
npx vitest run	690 passed (74 files)
npm run build	clean
stale "coming soon"/id0000 copy	none remaining
changelog sync	✓

The render path is {macosAppStoreUrl ? <App Store link> : <coming soon>} and the value is now a non-empty constant, so the link branch renders. A live curl check wasn't possible here — the download page requires setup to be completed, and the local dev instance isn't — so visual confirmation belongs on the demo after it picks this up.

Rolling it out

Two ways, no waiting required:

• Now: set the App Store URL in Admin → Site settings → Download on the demo (it overlays the default live, no restart).
• On next update: the new default flows through automatically on npm run update — no config needed, since the demo doesn't set an empty override.

🤖 Generated with Claude Code