Port 465/545A visual chrome from mcltspice docs into SpiceBook as a
toggleable waveform viewer skin. uPlot chart renders inside a CRT
screen with teal phosphor traces, graticule overlay, and scanlines.
Functional knobs control trace visibility (setSeries), X/Y zoom
(setScale) in standard 1-2-5 div steps. Digital readout bar shows
current trace, div values, and analysis type. Two switchable hardware
skins — 465 tan and 545A hammertone — persisted in localStorage.
New files: ScopeWaveformViewer.tsx, scope-skin.css
Modified: WaveformViewer.tsx (toggle), waveform-utils.ts (scope
palette, 1-2-5 sequence, stack-safe min/max), globals.css (scope vars)
