[Later / needs design] Optional cloud backup (e.g. Google Drive) for settings & history

[subhasisbiswal012]

Summary

For a later stage: let users optionally back up their Vitreous data (settings + Reflections history) to the cloud — e.g. their own Google Drive — so they can restore after a reinstall or move between machines.

⚠️ Principle check (read before building)

Vitreous is local-first, private by design — no backend, no server, no accounts (see CLAUDE.md / PROJECT-PLAN.md). A naive "Google backup" conflicts with that. To stay true to the project's values, any cloud backup MUST be:

• Strictly opt-in and user-initiated — never on by default, never required.
• Into the user's own storage (their Google Drive), with no Vitreous-operated server in the middle.
• Transparent about what's uploaded; ideally the backup bundle is just the local files the user already owns.
• Easy to turn off / delete.

This needs a short design discussion before implementation to confirm it doesn't undermine the no-server / no-account promise. Consider whether a plain local export/import (#8) plus the user putting that file in any cloud folder already satisfies most of this need without OAuth.

Possible scope (future)

• OAuth directly to the user's Google Drive (no intermediary server).
• Upload/download a backup bundle: settings.json + events.jsonl (reuse the export format from Reflections: import & export activity history #8).
• Manual "Back up now" / "Restore" actions; optional periodic backup.
• Clear status of last backup time; ability to disconnect and remove.

Status

Deferred / later phase. Blocked on a design decision about whether/how cloud sync fits the local-first principle. Depends on #8 (export/import) as the foundation.