dashboard: sort platforms by percentage descending

src/server/dashboard.zig

···
     const total = platforms.soundcloud + platforms.bandcamp + platforms.spotify + platforms.plyr;
 
     if (total > 0) {
-        // helper to format percentage - shows "<1%" for non-zero values that round to 0
         const PlatformData = struct { name: []const u8, count: u64, color: []const u8 };
-        const platform_list = [_]PlatformData{
+        var platform_list = [_]PlatformData{
             .{ .name = "soundcloud", .count = platforms.soundcloud, .color = "#ff5500" },
             .{ .name = "bandcamp", .count = platforms.bandcamp, .color = "#1da0c3" },
             .{ .name = "spotify", .count = platforms.spotify, .color = "#1db954" },
             .{ .name = "plyr.fm", .count = platforms.plyr, .color = "#7c3aed" },
         };
+
+        // sort by count descending
+        std.mem.sort(PlatformData, &platform_list, {}, struct {
+            fn cmp(_: void, a: PlatformData, b: PlatformData) bool {
+                return a.count > b.count;
+            }
+        }.cmp);
 
         for (platform_list) |p| {
             const pct: f64 = @as(f64, @floatFromInt(p.count)) / @as(f64, @floatFromInt(total)) * 100.0;