Fix double file picker on audioZone click

Guard against INPUT clicks bubbling up to zone handler,
which caused the file picker to open twice.

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

assets/js/tools.js

@@ -773,6 +773,7 @@ function setupAudio() {
 
   els.audioZone.addEventListener('click', (e) => {
     if (e.target === els.audioClear || els.audioClear?.contains(e.target)) return;
+    if (e.target === els.audioInput) return;
     if (e.target.tagName === 'LABEL') return;
     els.audioInput.click();
   });