chore: added warnings

Warning 1: if elements have the same name, show a warning.
Warning 2: if a goal/triggerNode has no/empty plan, show a warning.
Warning 3: if (non-phase) elements start with or are a number,
    show a warning.

src/pages/VisProgPage/visualProgrammingUI/VisProgStores.tsx

@@ -240,10 +240,14 @@ const useFlowStore = create<FlowState>(UndoRedo((set, get) => ({
         ).then(() => {
           get().unregisterNodeRules(nodeId);
           get().unregisterWarningsForId(nodeId);
+          // Re-validate after deletion is finished
+          get().validateDuplicateNames(get().nodes);
         });
       } else {
+        const remainingNodes = get().nodes.filter((n) => n.id !== nodeId);
+        get().validateDuplicateNames(remainingNodes); // Re-validate survivors
         set({
-        nodes: get().nodes.filter((n) => n.id !== nodeId),
+        nodes: remainingNodes,
         edges: get().edges.filter((e) => e.source !== nodeId && e.target !== nodeId),
         })
       }
@@ -265,15 +269,49 @@ const useFlowStore = create<FlowState>(UndoRedo((set, get) => ({
    */
   updateNodeData: (nodeId, data) => {
     get().pushSnapshot();
-    set({
-      nodes: get().nodes.map((node) => {
-        if (node.id === nodeId) {
-          node = { ...node, data: { ...node.data, ...data }};
-        }
-        return node;
-      }),
+    const updatedNodes = get().nodes.map((node) => {
+      if (node.id === nodeId) {
+        return { ...node, data: { ...node.data, ...data } };
+      }
+      return node;
+    });
+
+    get().validateDuplicateNames(updatedNodes); // Re-validate after update
+    set({ nodes: updatedNodes });
+  },
+
+  //helper function to see if any of the nodes have duplicate names
+  validateDuplicateNames: (nodes: Node[]) => {
+    const nameMap = new Map<string, string[]>();
+
+    // 1. Group IDs by their identifier (name, norm, or label)
+    nodes.forEach((n) => {
+      const name = (n.data.name || n.data.norm )?.toString().trim();
+      if (name) {
+        if (!nameMap.has(name)) nameMap.set(name, []);
+        nameMap.get(name)!.push(n.id);
+      }
+    });
+
+    // 2. Scan nodes and toggle the warning
+    nodes.forEach((n) => {
+      const name = (n.data.name || n.data.norm )?.toString().trim();
+      const isDuplicate = name ? (nameMap.get(name)?.length || 0) > 1 : false;
+
+      if (isDuplicate) {
+        get().registerWarning({
+          scope: { id: n.id },
+          type: 'DUPLICATE_ELEMENT_NAME',
+          severity: 'ERROR',
+          description: `The name "${name}" is already used by another element.`
+        });
+      } else {
+        // This clears the warning if the "twin" was deleted or renamed
+        get().unregisterWarning(n.id, 'DUPLICATE_ELEMENT_NAME');
+      }
     });
   },
+  
 
   /**
    * Adds a new node to the flow store.