Updates the CI publish pipeline so beta branch builds create and upload desktop releases to a dedicated GitHub repo, adds a beta-specific Tauri config/updater endpoint, and adjusts download routing to include a channel segment. This cleanly separates stable vs beta distribution and ensures release/edit/upload steps target the correct repository via a GH_REPO env and committer token. Concerns: the workflow hardcodes a beta repo name and relies on elevated credentials/tokens (and force-push/cherry-pick logic), so misconfiguration could publish to the wrong repo or introduce security/permissions issues.