feat: electrical simulation via ngspice-WASM (eecircuit-engine)
Adds full SPICE-accurate electrical simulation to Velxio, behind a lazy-
loaded ⚡ toolbar toggle. Arduino / ESP32 / RP2040 sketches now co-simulate
with real analog behaviour: correct voltages on wires, real I–V curves on
LEDs, working potentiometers, NTC thermistors read by analogRead(), PWM
driving RC filters, transistors, op-amps, diodes, MOSFETs, etc.
Engine: eecircuit-engine (ngspice compiled to WebAssembly). Main bundle
stays at 2.4 MB; the 20 MB SPICE chunk only loads when the user activates
electrical mode. Disabled at build time via VITE_ELECTRICAL_SIM=false.
Frontend additions:
- simulation/spice/: SpiceEngine wrapper + lazy entry, NetlistBuilder with
UnionFind over wires, componentToSpice mapping (24 metadataIds incl.
real part numbers: 2N2222, 2N3055, BC547, IRF540, 2N7000, 1N4148,
1N4007, 1N4733, LEDs, NTC, op-amp ideal), CircuitScheduler with
debounced coalescing, AVRSpiceBridge for quasi-static co-simulation.
- store/useElectricalStore: Zustand slice, feature-flag aware.
- components/analog-ui/: ⚡ toolbar toggle + SVG voltage overlay.
- components/components-instruments/: Voltmeter, Ammeter probes.
- 62 tests (spice-*, netlist-builder, component-to-spice, instruments).
Sandbox (test/test_circuit/): 47-test validation sandbox that proved
the approach (hand-rolled MNA baseline + ngspice pipeline) before
porting to the app. Kept as reference.
Docs: docs/wiki/circuit-emulation-*.md (13 engineering pages covering
architecture, solvers, components, AVR bridge, gotchas, performance,
integration plan, API reference, appendix) + electrical-simulation-
user-guide.md (end-user facing).
Reference plan: test/test_circuit/plan/phase_8_velxio_implementation.md
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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