perf(weather): apply the infrared cloud transfer from a lookup table, in place

The Satellite clouds transfer ran a power curve per pixel and wrote the
result back from a full-size copy. On the 4096x2048 images the 3D Tiles
host draws, that held the page for about 150 ms per image. The scale
depends only on the brightest channel, so it is now worked out once per
byte value and applied to the canvas pixels in place. Output bytes are
unchanged.

Co-Authored-By: Claude Fable 5.2 <[email protected]>

src/layers/weather/infraredImage.js

@@ -6,7 +6,7 @@ import {
   drawWeatherPixels,
   closeWeatherPixels,
 } from './source.js';
-import { infraredAlpha } from './infraredAlpha.js';
+import { applyInfraredAlpha } from './infraredAlpha.js';
 
 export const MAX_MOSAIC_BYTES = 4 * 1024 * 1024;
 
@@ -31,7 +31,8 @@ export function processInfraredImage(
 
 function applyInfraredTransfer(context, canvas, mode) {
   const pixels = context.getImageData(0, 0, canvas.width, canvas.height);
-  pixels.data.set(infraredAlpha(pixels.data, mode));
+  // In place: a copy of a 4096×2048 image is 33 MB, made and written back.
+  applyInfraredAlpha(pixels.data, mode);
   context.putImageData(pixels, 0, 0);
 }