initial: code-sinth — DSL-driven modular synth (Python engine + web app)

Patch language with osc/noise/trig/seq/adsr/filter/delay/poly + voice templates
and inline live values. Two runtimes:

- code_sinth/ — Python engine (numpy + sounddevice). Hot-reload via mtime
  watcher. Offline render to WAV. Static-HTTP+WS visualizer (viz/) that
  injects waveforms next to each `node X = ...` line.
- web/ — port of the engine to JS running in AudioWorklet. Single static
  page with CodeMirror 6 editor (line widgets for live waveforms) and a
  control surface on the right with knobs/faders/step_seq/piano_roll
  declared from the patch. State preserved across hot-reload.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

examples/perc.patch

@@ -0,0 +1,7 @@
+# Hi-hat: ruido blanco filtrado en pasa-altos con envolvente percusiva.
+node g1 = trig(period=0.5, duration=0.01)
+node ne = adsr(a=0.001, d=0.06, s=0.0, r=0.04, gate=g1)
+node n1 = noise()
+node hp = filter(hp, in=n1, cutoff=4000, q=1.0)
+
+out <- hp * ne