Add a server icon for the multiplayer list

tools/make_server_icon.ps1

@@ -0,0 +1,77 @@
+# Generates data/server-icon.png: the 64x64 image Minecraft shows beside the
+# server in the multiplayer list. Original pixel art, no Mojang assets.
+#
+# Drawn on a 16x16 logical grid at 4px per cell so it stays crisp pixel art
+# rather than a resized photo, and reads at the ~32px the launcher renders it.
+# Palette is the EduCraft house style already in the website's styles.css, so
+# the icon, the site and the guide book all look like one thing.
+Add-Type -AssemblyName System.Drawing
+
+$palette = @{
+  '.' = '#FBF7EF'   # cream-1, sky
+  'c' = '#F6EFE0'   # cream-2, soft cloud band
+  'h' = '#C96B62'   # rose highlight
+  '#' = '#B0524A'   # rose-1, heart body
+  '@' = '#8E3F39'   # rose-0, heart shadow
+  # PowerShell hashtable keys are case-insensitive, so g/G would collide.
+  'g' = '#7A8A5E'   # olive-2, grass top
+  '+' = '#5D6B47'   # olive-1, grass
+  'd' = '#465236'   # olive-0, soil
+  'o' = '#A9772E'   # ochre-1, lantern glow
+}
+
+# 16 rows of 16 characters.
+# Heart is a symmetric 12-wide form centred in the 16 grid, with a highlight on
+# the upper-left lobe and a one-pixel shadow down the lower-right edge, so it
+# reads as a lit object rather than a flat silhouette at launcher size.
+$grid = @(
+  '................'
+  '.....c......c...'
+  '....hh#..###....'
+  '...hh########...'
+  '..hh##########..'
+  '..############..'
+  '...#########@...'
+  '....#######@....'
+  '.....#####@.....'
+  '......###@......'
+  '.......#@.......'
+  '................'
+  '................'
+  '................'
+  'ggggoggggggoggg.'
+  '++dd++dd++dd++dd'
+)
+
+$cell = 4
+$size = 64
+$bmp = New-Object System.Drawing.Bitmap($size, $size)
+$g = [System.Drawing.Graphics]::FromImage($bmp)
+$g.SmoothingMode = 'None'
+$g.InterpolationMode = 'NearestNeighbor'
+
+for ($row = 0; $row -lt 16; $row++) {
+  $line = $grid[$row]
+  for ($col = 0; $col -lt 16; $col++) {
+    $ch = $line[$col]
+    $hex = $palette["$ch"]
+    if (-not $hex) { $hex = $palette['.'] }
+    $color = [System.Drawing.ColorTranslator]::FromHtml($hex)
+    $brush = New-Object System.Drawing.SolidBrush($color)
+    $g.FillRectangle($brush, $col * $cell, $row * $cell, $cell, $cell)
+    $brush.Dispose()
+  }
+}
+
+$g.Dispose()
+$out = 'F:\minecraft\data\server-icon.png'
+$bmp.Save($out, [System.Drawing.Imaging.ImageFormat]::Png)
+$bmp.Dispose()
+
+$f = Get-Item $out
+$check = [System.Drawing.Image]::FromFile($out)
+"wrote $out"
+"  dimensions: $($check.Width)x$($check.Height)  (Minecraft requires exactly 64x64)"
+"  size: $($f.Length) bytes"
+"  format: $($check.RawFormat)"
+$check.Dispose()