improve build times by extracting asset opt into its own crate (#3273)

* improve build types by extracing asset opt as a dylib
* dont use dylib, but let regular workspace caching do the heavy lifting
* add prebuild to cli for better lock contention
* hoist deps
* disable slow tests
* re-enable sequential, debug=0 for dev
* use vfs for windows
* dont cache on failure, fix windows vfs caceh
* free disk space re-order
* add clippy + fmt to windows channel
* yoink makefile
* proper rustfmt/clippy on toolchain
* set incremental to zero since cargo-cache disables it

packages/cli-opt/src/image/png.rs

@@ -0,0 +1,52 @@
+use std::{io::BufWriter, path::Path};
+
+use image::DynamicImage;
+
+pub(crate) fn compress_png(image: DynamicImage, output_location: &Path) {
+    // Image loading/saving is outside scope of this library
+    let width = image.width() as usize;
+    let height = image.height() as usize;
+    let bitmap: Vec<_> = image
+        .into_rgba8()
+        .pixels()
+        .map(|px| imagequant::RGBA::new(px[0], px[1], px[2], px[3]))
+        .collect();
+
+    // Configure the library
+    let mut liq = imagequant::new();
+    liq.set_speed(5).unwrap();
+    liq.set_quality(0, 99).unwrap();
+
+    // Describe the bitmap
+    let mut img = liq.new_image(&bitmap[..], width, height, 0.0).unwrap();
+
+    // The magic happens in quantize()
+    let mut res = match liq.quantize(&mut img) {
+        Ok(res) => res,
+        Err(err) => panic!("Quantization failed, because: {err:?}"),
+    };
+
+    let (palette, pixels) = res.remapped(&mut img).unwrap();
+
+    let file = std::fs::File::create(output_location).unwrap();
+    let w = &mut BufWriter::new(file);
+
+    let mut encoder = png::Encoder::new(w, width as u32, height as u32);
+    encoder.set_color(png::ColorType::Rgba);
+    let mut flattened_palette = Vec::new();
+    let mut alpha_palette = Vec::new();
+    for px in palette {
+        flattened_palette.push(px.r);
+        flattened_palette.push(px.g);
+        flattened_palette.push(px.b);
+        alpha_palette.push(px.a);
+    }
+    encoder.set_palette(flattened_palette);
+    encoder.set_trns(alpha_palette);
+    encoder.set_depth(png::BitDepth::Eight);
+    encoder.set_color(png::ColorType::Indexed);
+    encoder.set_compression(png::Compression::Best);
+    let mut writer = encoder.write_header().unwrap();
+    writer.write_image_data(&pixels).unwrap();
+    writer.finish().unwrap();
+}