fix: CreateConnection crash — hasDetailsChanged used before declaration

The useMemo for hasDetailsChanged was declared after the useCallback
(handleCreateOrUpdate) that references it in its dependency array.
JavaScript's temporal dead zone causes a ReferenceError when the
useCallback closure captures the variable before the useMemo
initializes it. Moved the useMemo above the useCallback.

Introduced by PR #57 (connection name/description edit fix).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: abhizipstack

frontend/src/base/components/environment/CreateConnection.jsx

@@ -125,6 +125,14 @@ const CreateConnection = ({
     getConnectionFields();
   }, [getConnectionFields]);
 
+  const hasDetailsChanged = useMemo(() => {
+    if (!connectionId || !originalDbSelectionInfo) return false;
+    return (
+      formName !== originalDbSelectionInfo.name ||
+      formDescription !== originalDbSelectionInfo.description
+    );
+  }, [connectionId, formName, formDescription, originalDbSelectionInfo]);
+
   const handleCreateOrUpdate = useCallback(async () => {
     setIsCreateOrUpdateLoading(true);
     try {
@@ -407,15 +415,6 @@ const CreateConnection = ({
     [dbSelectionInfo.datasource_name, selectedOrgId, csrfToken, connType]
   );
 
-  // Detect if connection name or description changed (metadata-only changes)
-  const hasDetailsChanged = useMemo(() => {
-    if (!connectionId || !originalDbSelectionInfo) return false;
-    return (
-      formName !== originalDbSelectionInfo.name ||
-      formDescription !== originalDbSelectionInfo.description
-    );
-  }, [connectionId, formName, formDescription, originalDbSelectionInfo]);
-
   const mappedDataSources = useMemo(
     () =>
       dataSources.map((dSource) => ({