[tylerthecoder]

The Universe Google Drive backup currently lives only in a local script and LaunchAgent. Add an universe-gdrive-backup setup to Owl's mac nest so the hourly mirror can be reproduced from versioned configuration.

• Mirror ~/Universe/, including notes and Git history, to the selected Google Drive account's My Drive/Universe Backup/. Preserve the existing exclusions and rsync --delete behavior: this is a mirror with propagated deletions, not a versioned archive. Google Drive desktop uploads the local mirror asynchronously.
• Generate the existing per-user LaunchAgent label with a one-hour interval and RunAtLoad. Retain previous plist files, support account selection and dry-run previews, and require no root access or stored credentials.
• Refuse missing source/mount directories, overlapping paths, and a symlink destination; serialize runs and propagate rsync failures.
• Include installation, disable/re-enable, logs, and troubleshooting documentation. No Syncthing changes.

Validation on macOS:

• Nine Python unittest cases pass, including real rsync against isolated temporary folders, note/Git copying, destination-only deletion, dry-run, missing directories, unsafe paths, concurrent runs, failure handling, and mocked LaunchAgent installation.
• bash -n, git diff --check, cargo check --no-default-features, and cargo test --no-default-features pass (the Rust suite contains zero tests).
• Owl's absolute-path setup info preview passes for the new setup; worktree mac dependencies and local asset paths validated separately. owl nest info passes for the configured existing mac nest. These read-only commands use the user's existing Owl configuration, which points at the original checkout, not the PR worktree.
• owl setups-validate reports four pre-existing failures due to missing local secrets.sh and dependent nests. cargo fmt --check and cargo clippy --no-default-features --all-targets -- -D warnings fail in untouched Rust files. Opened as a draft pending those repository-wide checks; no unrelated Rust cleanup included.

The live backup was not replaced or reinstalled. Real launchctl installation and Google Drive cloud upload were not exercised; tests mock launchctl. Installing this setup later replaces the same user job and starts an immediate mirror run.