Zoom the Parametric EQ's dB with the wheel, saved on its node (#376)

Close moves of a few dB were hard to set and to see on a curve that
always spans -24 to +24 dB. The wheel on free space now zooms the dB
the curve shows, and the node's small curve shows the same range.

- The range is one of ±3, ±6, ±12, ±24 and ±48 dB, always the same
  either side of 0. Up zooms in.
- It is saved on the node as `range`, so it is back after loading.
  Like the game scale (#226) it is no undo step. EditorState gets
  `setNodeView` for such a setting of a node.
- The lines across the curve follow the range: every 1, 2, 3, 6 or
  12 dB. A handle whose gain lies beyond the range stays on the edge,
  in sight and in reach.
- The wheel over a handle still turns the band's Q. It no longer does
  so anywhere while a band is picked: after opening, a band nearly
  always is, and the zoom would be out of reach.
- `EqArea` carries the range, so the tab and the node map dB alike.
  The spectrum keeps its own scale.

Tests:
- Unit parametric-eq: 16 green, 5 new (range in compile and save,
  node picture, wheel steps, grid lines, handle on the edge)
- Counter-check: the node's picture without the saved range turns
  the new picture test red
- e2e 34 (melektaus-atx): ALL PASSED, 99 checks, 1 new
- Gate (melektaus-atx): CHECK EXIT 0, 275 files, 4252 tests

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

tools/e2e/34-sound.mjs

@@ -571,6 +571,32 @@ export async function sound(t) {
       eqWheeled.q > 1,
     JSON.stringify({ eqDragged, eqUndone, eqWheeled }),
   );
+  // #376: the wheel on free space zooms the curve to ±12 dB, so the band's handle moves out with its
+  //       gain. The zoom is saved on the node, the Q stays, and Ctrl+Z undoes the Q, not the zoom.
+  const eqFree = await json('__gm.eq.pointAt(50, 12)');
+  await t.wheel(eqFree.x, eqFree.y, -100);
+  const eqZoomed = await json(`({
+    range: __gm.eq.range(),
+    saved: __gm.state.project.assets.find((a) => a.id === ${JSON.stringify(fxId)}).graph.nodes
+      .find((n) => n.id === 'fx-eq').params.range,
+    q: __gm.eq.bands()[0].q,
+    handle: __gm.eq.handleAt(0),
+    at: __gm.eq.pointAt(4000, -6),
+  })`);
+  await press('z', { ctrl: true });
+  const eqZoomUndone = await json('({ range: __gm.eq.range(), q: __gm.eq.bands()[0].q })');
+  await press('z', { ctrl: true, shift: true });
+  check(
+    'the wheel on free space zooms the curve to ±12 dB, saved on the node, and Ctrl+Z leaves the zoom',
+    eqZoomed.range === 12 &&
+      eqZoomed.saved === 12 &&
+      eqZoomed.q === eqWheeled.q &&
+      eqZoomed.handle.y > eqHandleBack.y + 10 &&
+      Math.abs(eqZoomed.handle.y - eqZoomed.at.y) < 1 &&
+      eqZoomUndone.range === 12 &&
+      eqZoomUndone.q < eqWheeled.q,
+    JSON.stringify({ eqHandleBack, eqZoomed, eqZoomUndone }),
+  );
   await shot('34-parametric-eq');
   // #374: floated beside the Sound FX tab, the EQ's tab draws the spectrum of what passes the node:
   //       the blip's 880 Hz is the loudest bin in front of the EQ and behind it. Once the tab is not