Function open_encrypted 

pub fn open_encrypted(
    path: &Path,
    k_intermediate: &SecretBox<[u8; 32]>,
    read_only: bool,
) -> DbResult<Connection>

Opens a database, applies the encryption key, and configures the connection.

This is the standard open sequence for encrypted databases: open -> key -> verify -> configure (WAL + foreign keys).

See the module-level documentation for the full encryption flow.

Errors

Returns Error if opening, keying, or configuring the connection fails.