fix: skip ResearchTreeScreen graph rebuild when registry is unchanged

buildGraph() was called unconditionally every 20 ticks (once per
second), performing a full teardown and reconstruction even when no
data had changed. A graphDirty flag now gates rebuilds; the flag is
only set when ResearchRegistry.size() changes (e.g. on datapack reload).

Author: MrSilly07

src/main/java/com/researchcube/client/screen/ResearchTreeScreen.java

@@ -100,6 +100,8 @@ private record Dependency(ResourceLocation sourceId, EdgeStyle style) {}
     private int graphMaxX;
     private int graphMaxY;
     private int refreshTicks = 0;
+    private int lastRegistrySize = -1;
+    private boolean graphDirty = true;
 
     public ResearchTreeScreen(ResearchTableMenu menu, Inventory playerInv, Component title) {
         super(menu, playerInv, title);
@@ -142,6 +144,14 @@ public void containerTick() {
         super.containerTick();
         refreshTicks++;
         if (refreshTicks % 20 == 0) {
+            int currentSize = ResearchRegistry.size();
+            if (currentSize != lastRegistrySize) {
+                graphDirty = true;
+                lastRegistrySize = currentSize;
+            }
+        }
+        if (graphDirty) {
+            graphDirty = false;
             buildGraph();
             clampPan();
         }