Function read_full 

pub fn read_full(
    conn: &Connection,
    memory_id: i64,
) -> Result<Option<MemoryRow>, AppError>

Fetches a live memory by primary key and returns all columns.

Mirrors read_by_name but keyed on rowid for use after a KNN search.

Errors

Returns Err(AppError::Database) on any rusqlite failure.