Add a Tracked trait and a Lookahead harness to common-dsp. Each engine is
now its tracker plus a module that follows note events aligned with its
input, so the same module can run behind a shared tracker.
Lathe and Temper output is bit-exact against the old engines. Knurl's
interpolation now reads one newer sample inside the module, so its
latency is one sample longer; the output matches within float rounding.
Each editor exposes body() and toggles() besides show(), so another
editor can draw a module's page.
Lathe places EQ bands on harmonics 1-32 of the played note, so a cut on
harmonic 3 stays on harmonic 3 on every note. Temper normalises each
note's level before an oversampled shaper and tunes its floor, push and
bright filters to the note, so every note distorts the same.
The note tracker moves from Anvil into common-dsp, together with a
state-variable filter, 4x oversampler and harmonic meter. Anvil's
behaviour and editor render are unchanged.
docs/ideas.md collects all plugin ideas and their status.
nvrl