Open a Compressor as a device in a window of one size (#379)

The tab from #378 shows a Compressor as an editor. The user wanted it
to look like a device as well, after a brushed aluminium plug-in, with
a meter of the gain reduction instead of the pictures. The tab stays
and is switched to per node.

- Hardware look is a switch under Settings, on by default for new and
  existing Compressors. Only the editor reads it.
- The panel is 820x280 px and opens straight in a window of that size.
  The window has no sizing corner and no Dock. A pane says so through
  `fixedSize`, and `keptSize` keeps the window's middle when it
  changes to that size.
- A Compressor in this look never sits in the tab row. Opening one
  floats it, and switching the look on moves its tab into the window.
- The panel has chrome knobs (threshold and makeup large), a meter
  with a needle that moves like a VU's, an LCD with the name and the
  reading, a lever with a lamp for auto-gain, and LEDs for the level
  going out. Everything is drawn in code.
- The Knob takes a size and a chrome look, and leaves out its caption
  when it has no name, so the panel engraves its own.
- `autoGainOn` is now `switchOn`, because the new switch reads the
  same way.
- Where parts sit, the meter's scale, the needle's speed, the LEDs and
  the plate's grain are in `hardwareView.ts`, apart from the drawing.

Decided myself:
- The meter's scale runs by the square root, so the first dB is about
  as wide as the last nine. It is red from 10 dB on.
- The LEDs light one every 3 dB from -39 to 0 dB and fall by 20 dB a
  second.
- Switching the look changes the graph's fingerprint, like any other
  setting of a node. The sound FX is built again once.

Findings, fixed on the way:
- Pixi's `arc` goes on from the last point of the path. The meter's
  scale had a line from the corner of the face until each arc got a
  `moveTo` to its own start.
- A text put into a Graphics makes Pixi warn that only Containers take
  children. The LCD is a Container now.
- The first browser check read the needle at one moment and missed the
  short sound. The panel keeps the most its needle and LEDs showed.

Tests:
- Unit: hardware-view (10 new), documents (1 new)
- e2e 34 (melektaus-atx): ALL PASSED, 122 checks (4 new). Played,
  the needle reached 20.9 dB and 5 LEDs lit.
- Gate (melektaus-atx): CHECK EXIT 0, 283 files, 4355 tests (11 new)
- Counter-checks: a window that keeps its corner instead of its
  middle, and a linear meter scale, each turn exactly their test red.

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

tests/editor/documents.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from 'vitest';
 import { closeDocument, neighbourOf, openDocument, replaceDocument } from '../../src/editor/documents';
 import {
+  keptSize,
   leastBox,
   MIN_WINDOW_HEIGHT,
   MIN_WINDOW_WIDTH,
@@ -104,6 +105,13 @@ describe('a tab in a window (#371)', () => {
     expect(onScreen({ ...box, w: 400, h: 300 }, 1280, 800, least)).toEqual({ ...box, w: 701, h: 450 });
     expect(onScreen({ ...box, w: 400, h: 300 }, 600, 400, least)).toEqual({ x: 0, y: 0, w: 600, h: 400 });
   });
+
+  it('takes the size of a pane of one size around the middle it had, and keeps a box of that size (#379)', () => {
+    const box = { x: 100, y: 100, w: 800, h: 600 };
+    expect(keptSize(box, { w: 400, h: 200 })).toEqual({ x: 300, y: 300, w: 400, h: 200 });
+    const kept = { x: 7, y: 9, w: 400, h: 200 };
+    expect(keptSize(kept, { w: 400, h: 200 })).toBe(kept);
+  });
 });
 
 describe('tab row without an active tab', () => {