fix(common): decode the crop view image at screen resolution

[farfromrefug]

Summary

CropView derived its decode size from Screen.mainScreen.widthDIPs/heightDIPs, but that value reaches decoders that expect pixels: decodeWidth ends up in Fresco's ResizeOptions, and the magnifier's loadImage({ resizeThreshold }) goes to the native processor. On a 1080x2340 screen the image was decoded at 780px and then upscaled to fill the view, so the photo shown right after a capture looked markedly blurrier than the camera preview it replaces — even though the captured file itself is sharp.

• Reuse IMAGE_DECODE_HEIGHT (widthPixels/heightPixels), which is already what the rest of the app passes as a decode size. On a 1080x2340 device that is 780 -> 2340.
• The magnifier loupe reads the same constant, so it sharpens too.

Note this decodes ~9x more pixels for that one bitmap, which is what every other image view in the app already does.

Testing

• npx eslint clean, svelte-check reports 0 errors
• built and installed on a Galaxy S22 (SM-S901U1); the blur was traced there with the actual files: the capture pulled off the device (4080x3060) is sharp at 1:1, the crop geometry is correct, and only the on-screen decode was undersized

A visual confirmation on device that the review screen now matches the preview's sharpness is still worth doing.