Viz graph: draw the fx chain as CONNECTED, directed nodes

Paul: 'show how the node graph works... I can't see how they're connected.' The per-voice chips were a floating list; now the chain is drawn as connected nodes with arrowheads — voice -> fx1 -> fx2 -> ... -> sends -> delay -> reverb -> master -> out — so the signal flow reads as a directed graph.

▶ Play it: Food Court Eternity — the brightest, most processed corner of the space https://stellate.app/?genre=vaporwave&seed=2619&path=1679.4393,1698.4426,1660.4426&xdur=13.122

132df3b https://github.com/aboard-io/stellate/commit/132df3bb13abce8a6c42f7f19c319d53d1edbab1