Import march-2020-03-10 from private repo (scrubbed 2026-05-27)

Targets Rec Room 2020.03.10 client (also serves 2020.03.06).

Re-import after adding:
- DorkNet.ClientMod/dorknet-clientmod.json.template — config schema
  the launcher's manifest-driven patcher renders into UserData/.
- tools/build-patcher-zip.ps1 — produces dorknet-clientpatch-{key}.zip
  for v1-march-* Release uploads.
- .github/workflows/release.yml — on tag push publishes both
  dorknet-server-march_2020_03_10-win-x64.zip and
  dorknet-clientpatch-march_2020_03_10.zip as Release assets.

Same scrub rules as december; tools/build-patcher-zip.ps1 added to
the maintainer-side allow-list so it survives.

DorkNet.Server/Services/ImageTransformService.cs

@@ -0,0 +1,65 @@
+using SkiaSharp;
+
+namespace DorkNet.Server.Services;
+
+/// <summary>
+/// img.* CDN transforms. The 2020 watch posts a full-frame capture
+/// (e.g. the avatar standing in their dorm) and then re-requests the
+/// same blob with <c>?cropSquare=1&amp;width=256</c> on the profile
+/// thumbnail surface. We honour <c>cropSquare</c> server-side so the
+/// profile pic is face-zoomed, but we deliberately ignore the watch's
+/// <c>width=256</c> hint and return the cropped image at the source's
+/// native resolution: the watch's UI renders the same blob across
+/// multiple sizes (small thumb chip and the big profile frame), and a
+/// pre-shrunk 256² source gets stretched across a ~500px UI element and
+/// looks blurry. Keeping the source resolution lets the watch's image
+/// pipeline downsample for display without losing detail.
+/// </summary>
+public static class ImageTransformService
+{
+    public readonly record struct Result(byte[] Bytes, string ContentType);
+
+    public static Result? TryTransform(
+        byte[] sourceBytes,
+        string sourceContentType,
+        bool cropSquare,
+        int? widthHint)
+    {
+        // widthHint is intentionally unused — see class comment. Kept on the
+        // signature so the controller can pass the parsed value without the
+        // call site having to know which params we currently respect.
+        _ = widthHint;
+        if (!cropSquare) return null;
+        if (sourceBytes.Length == 0) return null;
+
+        using var input = SKBitmap.Decode(sourceBytes);
+        if (input is null) return null;
+        if (input.Width == input.Height) return null; // already square, pass through
+
+        using var cropped = CenterCropSquare(input);
+        using var image = SKImage.FromBitmap(cropped);
+
+        // Re-encode in the same family the source advertised, so an uploaded
+        // JPEG stays JPEG (size budget for profile pic round-trips) and
+        // anything PNG-shaped stays PNG (alpha preserved for UI overlays).
+        var (format, contentType, quality) = sourceContentType switch
+        {
+            "image/jpeg" or "image/jpg" => (SKEncodedImageFormat.Jpeg, "image/jpeg", 92),
+            "image/webp"               => (SKEncodedImageFormat.Webp, "image/webp", 92),
+            _                          => (SKEncodedImageFormat.Png,  "image/png",  100),
+        };
+        using var encoded = image.Encode(format, quality);
+        return new Result(encoded.ToArray(), contentType);
+    }
+
+    private static SKBitmap CenterCropSquare(SKBitmap input)
+    {
+        var side = Math.Min(input.Width, input.Height);
+        var x = (input.Width - side) / 2;
+        var y = (input.Height - side) / 2;
+        var dst = new SKBitmap(new SKImageInfo(side, side, input.ColorType, input.AlphaType));
+        using var canvas = new SKCanvas(dst);
+        canvas.DrawBitmap(input, new SKRect(x, y, x + side, y + side), new SKRect(0, 0, side, side));
+        return dst;
+    }
+}