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/pad_delay.patch

@@ -0,0 +1,25 @@
+# Pad polifonico + delay sincronizado al rate (250ms = una nota).
+voice pad {
+    node o1  = osc(saw, freq=freq)
+    node o2  = osc(saw, freq=freq * 1.005)
+    node sum = (o1 + o2) * 0.5
+    node env = adsr(a=0.06, d=0.3, s=0.5, r=1.2, gate=gate)
+    node lp  = filter(lp, in=sum, cutoff=400 + env*1500, q=1.2)
+    out <- lp * env
+}
+
+node p = poly(
+    voice=pad, voices=8,
+    rate=4, gate_duration=0.6,
+    notes=[
+        261.63, 329.63, 392.00, 523.25,
+        220.00, 261.63, 329.63, 440.00,
+        174.61, 220.00, 261.63, 349.23,
+        196.00, 246.94, 293.66, 392.00
+    ]
+)
+
+node dry = p * 0.18
+node wet = delay(in=dry, time=0.375, feedback=0.35, mix=0.35)
+
+out <- wet