Drop the instance → fam-instance "= (Rhs)" edge

Drop the instance → fam-instance "= (Rhs)" edge

The dotted-purple edge from a focused instance to its associated
fam-instance carried only the RHS label, which the fam-instance
node's own label already shows in full. Removing it cleans up the
instance view; the fam-instance still surfaces because the family
node points at it via fam-defines, which is enough to indicate the
context relevance.

Also drop the now-dead cytoscape style rule and the legend row.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>