feat: reorganize files and implement ui and sidebar

lib/hooks/use-enter-submit.tsx

@@ -0,0 +1,20 @@
+import type { RefObject } from 'react'
+import { useRef } from 'react'
+
+export function useEnterSubmit(): {
+  formRef: RefObject<HTMLFormElement>
+  onKeyDown: (event: React.KeyboardEvent<HTMLTextAreaElement>) => void
+} {
+  const formRef = useRef<HTMLFormElement>(null)
+
+  const handleKeyDown = (
+    event: React.KeyboardEvent<HTMLTextAreaElement>
+  ): void => {
+    if (event.key === 'Enter' && !event.shiftKey) {
+      formRef.current?.requestSubmit()
+      event.preventDefault()
+    }
+  }
+
+  return { formRef, onKeyDown: handleKeyDown }
+}