Adds full array/waveform support through the synthetic DSP engine: a
dsp.Sample value model (scalar or []float64), array ops (index, slice,
sum, mean, min, max, length, fft) with an in-tree radix-2 FFT, and static
type propagation (OpOutputType) that the editor mirrors to colour wires by
data type and flag invalid wirings. Stateful filters and lua stay
scalar-only. Adds a waveform plot mode (x-vs-index trace).
Also: errored-node hover reasons, S/N add-signal/add-node HUD shortcuts in
the synthetic editor, and view-mode widgets that blend with the canvas
background (chrome kept in edit mode).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Martino Ferrari