ADR-0003: Use plain SQLite for application persistence

Status: Accepted

Context

Run history must be local, portable, and inspectable by operators and administrators. The project introduction describes SQLite as an open database file rather than an application-managed access boundary.

Decision

BHTune stores its templates, tune history, results, and audit records in a plain SQLite database. It does not encrypt the database or implement per-row access control.

Consequences

The database can be inspected and backed up with ordinary SQLite tools. File access and protection remain responsibilities of the host and its operating-system controls; BHTune does not provide a separate database security layer. The persistence policy describes the migration compatibility boundary.