When connecting to a vertex, the final via might cause a violation

[growly]

Ponder this:

The rule might need to be:

• when connecting to a vertex on the same layer as an incoming edge, if the edge we're connecting from is so short that a via at one end would leave a tiny stub at such a distance that a wire there could not be acommodated within min separation, fatten the whole edge; and/or
• check shapes nearby (i.e. that DRC feature we've been wanting)