fix(play): skip fullscreen shortcut when typing in text inputs

The window-level 'F' keydown listener now ignores events from INPUT,
TEXTAREA, and contentEditable elements so freeform input is not
interrupted by the presentation-mode toggle.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/[locale]/play/page.tsx

@@ -1503,6 +1503,8 @@ function PlayInner() {
 
   useEffect(() => {
     function onKey(e: KeyboardEvent) {
+      const tag = (e.target as HTMLElement)?.tagName;
+      if (tag === "INPUT" || tag === "TEXTAREA" || (e.target as HTMLElement)?.isContentEditable) return;
       if (e.key === "f" || e.key === "F") {
         if (e.metaKey || e.ctrlKey || e.altKey) return;
         e.preventDefault();