getPackedAttr
Returns the primary packed attribute word for the cell at col.
The primary word stores foreground/background colors plus the most common SGR flags. Renderers should read it together with getPackedExtendedAttr and decode both words with io.github.ketraterm.core.codec.AttributeCodec.
This method is intended for render loops and performs no allocation.
Return
Primary packed attribute word for the cell.
Parameters
col
Column index (0-based).