fd Directory Reference

Files
	reader.c
	For terminal fd reader, this is the live record that ties fp, frame_height, frame_width, line_buffer together. The owning code creates it, updates it while work is active, and releases its handles and pointed-to storage before freeing the record.
	writer.c
	terminal fd writer keeps the values that move through the subsystem: fp. Some members are pointers into caller- or subsystem-owned memory, so lifetime follows the API that populated them rather than the struct copy itself.