<< 5 mm radius to the endpoints of each line, then use these circles to cut the lines? This should too works for arcs

Vclone by Max can help you for this!

Work for only one extremity of something selected: Lines , arcs; curves etc...
So apply one time then select all lines Press Tab and write Flip
re-apply Vclone so all extremities will have their "circles" ;) (not shown here)