Enhancement: more complete magicksave support

Possible bug

Is this a possible bug in a feature of sharp, unrelated to installation?

[x] Running npm install sharp completes without error.
[x] Running node -e "require('sharp')" completes without error.

Are you using the latest version of sharp?

[x] I am using the latest version of sharp as reported by npm view sharp dist-tags.latest.

What is the output of running `npx envinfo --binaries --system --npmPackages=sharp --npmGlobalPackages=sharp`?

  System:
    OS: Linux 6.1 Debian GNU/Linux trixie/sid
    CPU: (8) x64 Intel(R) Core(TM) Ultra 9 185H
    Memory: 6.67 GB / 7.72 GB
    Container: Yes
    Shell: 5.2.15 - /bin/bash
  Binaries:
    Node: 20.18.0 - /usr/local/bin/node
    Yarn: 1.22.22 - /usr/local/bin/yarn
    npm: 10.8.2 - /usr/local/bin/npm
  npmPackages:
    sharp: ^0.33.5 => 0.33.5

Does this problem relate to file caching?

The default behaviour of libvips is to cache input files, which can lead to EBUSY or EPERM errors on Windows. Use sharp.cache(false) to switch this feature off.

[ ] Adding sharp.cache(false) does not fix this problem.

Does this problem relate to images appearing to have been rotated by 90 degrees?

Images that contain EXIF Orientation metadata are not auto-oriented. By default, EXIF metadata is removed.

To auto-orient pixel values use the parameter-less rotate() operation.
To retain EXIF Orientation use keepExif().
[ ] Using rotate() or keepExif() does not fix this problem.

What are the steps to reproduce?

Install sharp into empty project with custom libvips and ImageMagick on debian 12.
Read a bmp image.
resize the image and toBuffer.

Failed with messages:


> test-sharp@1.0.0 start
> node ./src/index.js

test { format: 'magick', width: 363, height: 363, space: 'srgb', channels: 3, depth: 'uchar', density: 72, isProgressive: false, pages: 1, resolutionUnit: 'cm', formatMagick: 'BMP3', hasProfile: false, hasAlpha: false, orientation: 1 } /root/test-sharp/node_modules/sharp/lib/output.js:163 const stack = Error(); ^

Error: Unsupported output format magick at Sharp.toBuffer (/root/test-sharp/node_modules/sharp/lib/output.js:163:17) at test (/root/test-sharp/src/index.js:17:6)

Node.js v20.18.0


### What is the expected behaviour?

<!-- Please enter the expected behaviour here. -->

Could save bmp image to buffer or to file with ImageMagick support.

### Please provide a minimal, standalone code sample, without other dependencies, that demonstrates this problem

<!-- Please provide either formatted code or a link to a repo/gist that allows someone else to reproduce here. -->

let origImg = sharp(imgPath);
console.log(await origImg.metadata());

let newImg = await origImg.resize({ width: 200, height: 200, fit: "outside", background: { r: 255, g: 255, b: 255, alpha: 1 } })
.toBuffer();



### Please provide sample image(s) that help explain this problem

<!-- Please provide links to one or more images here. -->

lovell / sharp