Fix an issue where the AI Assistant input textbox sometimes swallows the first character of input.

docs/en_US/release_notes_9_14.rst

@@ -31,3 +31,4 @@ Bug fixes
   | `Issue #9279 <https://github.com/pgadmin-org/pgadmin4/issues/9279>`_ -  Fixed an issue where OAuth2 authentication fails with 'object has no attribute' if OAUTH2_AUTO_CREATE_USER is False.
   | `Issue #9392 <https://github.com/pgadmin-org/pgadmin4/issues/9392>`_ -  Ensure that the Geometry Viewer refreshes when re-running queries or switching geometry columns, preventing stale data from being displayed.
   | `Issue #9721 <https://github.com/pgadmin-org/pgadmin4/issues/9721>`_ -  Fixed an issue where permissions page is not completely accessible on full scroll.
+  | `Issue #9740 <https://github.com/pgadmin-org/pgadmin4/issues/9740>`_ -  Fixed an issue where the AI Assistant input textbox sometimes swallows the first character of input.

web/pgadmin/tools/sqleditor/static/js/components/sections/NLQChatPanel.jsx

@@ -288,6 +288,7 @@ export function NLQChatPanel() {
   });
 
   const messagesEndRef = useRef(null);
+  const inputRef = useRef(null);
   const abortControllerRef = useRef(null);
   const readerRef = useRef(null);
   const stoppedRef = useRef(false);
@@ -366,6 +367,16 @@ export function NLQChatPanel() {
     messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
   }, [messages]);
 
+  // Auto-focus the input when loading completes
+  useEffect(() => {
+    if (!isLoading) {
+      // Defer focus to ensure the DOM has updated (disabled=false)
+      setTimeout(() => {
+        inputRef.current?.focus();
+      }, 0);
+    }
+  }, [isLoading]);
+
   // Force CodeMirror re-render when panel becomes visible (fixes tab switching issue)
   const [cmKey, setCmKey] = useState(0);
   useEffect(() => {
@@ -741,6 +752,7 @@ export function NLQChatPanel() {
 
       <InputArea>
         <TextField
+          inputRef={inputRef}
           fullWidth
           multiline
           minRows={1}