Asynchronous Git history

Context

Users need note history. Git offers durable Markdown diffs but filesystem writes and repository operations cannot enter editing or navigation paths.

Decision

SQLite remains authoritative. Successful document transactions append generic history_outbox rows. A background history adapter materializes stable notes/<uuid>.md paths and commits them. Cached headers use backend-neutral version IDs and feed UI.

Saves coalesce into one pending revision per editing burst: a save landing within HISTORY_COALESCE_WINDOW_MS (2 minutes) of a pending revision's first save updates that outbox row in place, and a pending revision only becomes claimable once the window has elapsed. The document itself is still persisted on every save; coalescing only bounds how many restore points a burst of typing produces.

Consequences

• Git failure never fails a note save.
• Outbox replay survives crashes.
• History is eventually consistent.
• Browser runtime may implement HistoryPort with SQLite revisions or remote history instead of Git.