fix: reset generated files cache when modal closes so reopening fetches fresh data

frontend/src/components/GenerateModal.tsx

@@ -1,4 +1,4 @@
-import { useState } from 'react'
+import { useState, useEffect } from 'react'
 import Dialog from '@mui/material/Dialog'
 import DialogTitle from '@mui/material/DialogTitle'
 import DialogContent from '@mui/material/DialogContent'
@@ -37,6 +37,10 @@ export default function GenerateModal({ open, configId, configName, onClose }: P
   const [files, setFiles] = useState<GeneratedFiles | null>(null)
   const [loading, setLoading] = useState(false)
 
+  useEffect(() => {
+    if (!open) setFiles(null)
+  }, [open])
+
   const handleOpen = async () => {
     if (files) return
     setLoading(true)