Fix menu buttons never rendering: reset canvas transform per repaint

The RcoRenderer applied translate/scale to the shared GraphicsContext on
every render, so repeated repaints (menu animations fire many) compounded
the scale and pushed the buttons off-screen. Reset the transform each
render. Also decompress zlib/RLZ RCO images (previously returned raw).

core/src/main/java/dev/quoije/umd/rco/RcoFile.java

@@ -261,10 +261,14 @@ public final class RcoFile {
                     int comp = read16();
                     int sizePacked = read32();
                     int imgOffset = read32();
+                    int sizeUnpacked = sizePacked;
                     if (comp != COMPRESSION_NONE) {
-                        skip(4); // sizeUnpacked
+                        sizeUnpacked = read32();
                     }
                     byte[] imgData = readImageData(imgOffset, sizePacked);
+                    if (imgData != null && comp != COMPRESSION_NONE) {
+                        imgData = decompressImage(imgData, comp, sizeUnpacked);
+                    }
                     images.put(entryOffset, new ImageObject(imgData));
                 }
             }
@@ -359,6 +363,32 @@ public final class RcoFile {
         return data;
     }
 
+    private byte[] decompressImage(byte[] packed, int comp, int sizeUnpacked) {
+        try {
+            if (comp == COMPRESSION_ZLIB) {
+                java.util.zip.Inflater inflater = new java.util.zip.Inflater();
+                inflater.setInput(packed);
+                byte[] out = new byte[sizeUnpacked];
+                int len = inflater.inflate(out);
+                inflater.end();
+                if (len != sizeUnpacked) {
+                    out = java.util.Arrays.copyOf(out, len);
+                }
+                return out;
+            } else if (comp == COMPRESSION_RLZ) {
+                byte[] out = new byte[sizeUnpacked];
+                int len = Lzr.decompress(out, out.length, packed);
+                if (len < 0) {
+                    return null;
+                }
+                return java.util.Arrays.copyOf(out, len);
+            }
+        } catch (Exception e) {
+            return null;
+        }
+        return packed;
+    }
+
     private String readLabel(int labelOffset) {
         int current = tell();
         seek(pLabelData + labelOffset);