Migrate desktop installer distribution to R2 / amd-gaia.ai when website lands #734

Context

PR #731 ships the desktop installer via GitHub Releases for v0.17.2. The original plan (docs/plans/desktop-installer.mdx §7 Phase 6) called for distributing via Cloudflare R2 at downloads.amd-gaia.ai/latest/. R2 was deferred because:

1. Cloudflare account ownership wasn't decided
2. The custom domain (downloads.amd-gaia.ai) needed DNS setup
3. GitHub Releases works fine as a stop-gap (free, no infra)

This issue tracks the eventual migration when the website / R2 infrastructure lands.

What needs to happen

Cloudflare side

1. Decide R2 ownership: AMD-managed Cloudflare account or shared with the website project?
2. Create R2 bucket gaia-releases with public read access
3. Set up custom domain downloads.amd-gaia.ai as a CNAME → R2 bucket
4. Generate API token with R2 write access scoped to gaia-releases

GitHub Action secrets (in amd/gaia repo)

Add:

• CF_API_TOKEN — Cloudflare API token from above
• CF_ACCOUNT_ID — your Cloudflare account ID
• R2_BUCKET — gaia-releases

Code changes (small)

1. .github/workflows/build-installers.yml — add an R2 upload step alongside the existing GitHub Releases upload, gated on CF_API_TOKEN being present. The step should sync dist-app/*.{exe,dmg,deb,AppImage,blockmap,yml} to r2://gaia-releases/v${VERSION}/ AND r2://gaia-releases/latest/.

2. src/gaia/apps/webui/electron-builder.yml — change the publish provider from GitHub to generic:

   publish:
     provider: generic
     url: https://downloads.amd-gaia.ai/latest/

3. Update the install guide (docs/guides/install.mdx) to point at https://downloads.amd-gaia.ai/<platform>/... instead of GitHub Releases.

4. Update README badges to point at https://downloads.amd-gaia.ai/.

Why bother with R2?

• Faster downloads for users outside North America (Cloudflare's CDN vs GitHub's single-region)
• Stable latest/ URL that doesn't require resolving the latest release tag
• No GitHub API rate limits for electron-updater (anonymous calls to public repos work but have low quotas at scale)
• Cleaner URL in marketing material (downloads.amd-gaia.ai/win/GAIA Setup.exe vs the long GH Releases URL)

When?

This is not blocking v0.17.2. PR #731 ships installers via GitHub Releases successfully. R2 migration happens when:

• The amd-gaia.ai website project is far enough along to justify the infra
• Download volume / user feedback suggests CDN performance matters

Until then, electron-updater uses the GitHub provider config in electron-builder.yml, which works fine for public repos with no auth.

See also

• Plan: docs/plans/desktop-installer.mdx §7 Phase 6 (deferred) + §10 Open Questions 1 & 2
• PR: feat: desktop installer for GAIA Agent UI (#530) #731