SQLite is canonical

Context

Markdown files are portable but make rich-editor round trips, tree metadata, atomic multi-record writes, search indexing, and crash recovery more complex.

Decision

SQLite stores canonical structured documents and metadata. Markdown is a transactional projection used for export, search, and history.

Consequences

• Navigation can hydrate structured documents without Markdown parsing.
• One transaction protects each logical write.
• External filesystem editing is excluded from initial scope.
• Export and backup must remain prominent because database files are not user-readable notes.