✨ feat: implement API key authentication and user session management

web/hooks/useFocusReturn.ts

@@ -0,0 +1,40 @@
+"use client";
+
+import { useCallback, useEffect, useRef } from "react";
+
+/**
+ * Saves the currently focused element and returns a function to restore focus to it.
+ * Use when opening modals/dialogs to return focus to the trigger on close.
+ *
+ * @example
+ * const returnFocus = useFocusReturn();
+ *
+ * const openDialog = () => {
+ *   returnFocus.save(); // call before showing the dialog
+ *   setOpen(true);
+ * };
+ *
+ * const closeDialog = () => {
+ *   setOpen(false);
+ *   returnFocus.restore(); // call after hiding the dialog
+ * };
+ */
+export function useFocusReturn() {
+  const savedRef = useRef<HTMLElement | null>(null);
+
+  const save = useCallback(() => {
+    savedRef.current = document.activeElement as HTMLElement | null;
+  }, []);
+
+  const restore = useCallback(() => {
+    if (savedRef.current && typeof savedRef.current.focus === "function") {
+      savedRef.current.focus();
+      savedRef.current = null;
+    }
+  }, []);
+
+  // Safety cleanup on unmount
+  useEffect(() => () => { savedRef.current = null; }, []);
+
+  return { save, restore };
+}