[INFRA] No downloadable ISO on GitHub Releases

[mikejmorgan-ai]

Problem

Users visiting the repo or website have no way to download CX Linux. The Getting Started page references "Download the ISO from our official site" but there is no ISO available.

Current State

• No GitHub Releases with ISO attachments
• No download links on website
• cx-distro can build ISOs but none are published

Required Actions

1. Build official ISO from cx-distro main branch
2. Create GitHub Release with:
   • cx-linux-0.1.0-amd64.iso
   • cx-linux-0.1.0-amd64.iso.sha256
   • Release notes
3. Update website with download button pointing to release

Priority

P0 - Critical (blocks marketing launch)

Acceptance Criteria

• ISO builds successfully in CI
• ISO uploaded to GitHub Releases
• SHA256 checksum provided
• Website download button works