Show a Bitcrusher node as a device that draws its pixels (#399)

A Bitcrusher only said what it does in rows of numbers. How coarse
its steps and holds are could not be seen. Now the node is a device
of its own size. Its screen sends a sine through the node's own crush
and draws what comes out in cells, as tall as a step and as wide as a
hold, so the coarser the crush, the coarser the picture.

- CrusherPanel draws a 680x280 plate in bubblegum pink. Bits and rate
  are large knobs, wet is small. Rate gives its low end more of the
  turn, 8 kHz sits just past the middle.
- crushTrace runs a 440 Hz sine at 0 dBFS through Crusher at 48 kHz
  and blends it as the worklet does. Where each hold starts comes from
  Crusher too: a ramp through it at 16 bits takes a new value per hold.
- cellOf shapes a hold. From 5 px a step or hold gets a grid line and
  a gap. Finer steps give a 2 px bar. A cell is never more than twice
  as tall as wide, so 1 bit gives bars at -1, 0 and 1.
- The screen shows two periods, or 6 holds where the rate is low. The
  sine going in is a grey ghost. Below wet 1 the heard line lies over
  the cells.
- Above the screen a word for how crushed it is, CLEAN to BROKEN.
  Under it the noise the bits leave and where the rate folds back.
- 16 lamps show the bits kept, the highest on the left. A CRUSH lamp
  beside the name glows the more it crushes.
- COLUMNS_OF gives the Bitcrusher 4 columns in the presets.
- Hook __gm.bitcrusher.panel(id) for the sound FX and instrument
  graphs.

Decided myself:

- The screen is still. Nothing on it moves, so tick() says false.
- How crushed counts whichever of bits or rate takes more, the rate in
  octaves, times wet.

Found: at 8 kHz the first hold is 7 samples long, the rest 6. Six
sixths add up to just under 1 in Crusher. The worklet does the same,
so the screen shows what is heard.

Every sfxr effect preset ends in a Bitcrusher and gets 3 columns
wider. The Laser preset still fits whole on Fit.

Tests:
- Unit: crusher-view 13 tests (new). The screen matches Crusher with
  its wet on three settings.
- Counter-test: without the wet in the blend the worklet test fails.
- e2e 34: ALL PASSED, 143 checks (1 new).
- Gate: CHECK EXIT 0, 292 files, 4484 tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/core/instrument/chipPresets.ts

@@ -396,10 +396,11 @@ const ROW = 340;
 /**
  * Columns a node takes that is drawn as its editor in the graph (#385): a Filter's curve is wide,
  * a Chip's device (#386) wider, an Envelope's (#388) a little less, a Pitch's and a Mix's (#390) two,
- * a Delay's (#393), a Phaser's and a Flanger's (#398) four.
+ * a Delay's (#393), a Phaser's, a Flanger's (#398) and a Bitcrusher's (#399) four.
  */
 const COLUMNS_OF: Readonly<Record<string, number>> = {
   [SoundFxFilter.type]: 4,
+  [SoundFxBitcrusher.type]: 4,
   [SoundFxDelay.type]: 4,
   [SoundFxPhaser.type]: 4,
   [SoundFxFlanger.type]: 4,