Adds a fourth scene for route summarization: two /24s in a /16 parent,
slider to position each, draws the smallest supernet that covers both.
Demonstrates cleanly why only consecutive and power-of-two aligned
subnets aggregate without collateral.
Adds a prose section on reserved IPv4 ranges (RFC 1918 private,
loopback, link-local, multicast, limited broadcast, 0.0.0.0, RFC 6598
CGN space).
Fixes scene-samesubnet layout where the host title strips were
overlapping the bit rows; increases row gap so titles sit cleanly above
their rows. Clamps pill labels in scene-supernet so they stay on
canvas when subnets sit at the track edges, and fixes an off-by-one
tick label that read '10.20.256.0' at the right edge.
Also retitles the post.
Graham McIntire
87368d28d7