fix: refresh recognition.lang before dictation start

After a runtime locale change (setLocale from Settings), the cached
recognition object retains its boot-time lang, causing dictation to
run in the wrong language. Set lang immediately before .start() at
the plain dictation path in _startMicCapture, matching the pattern
already used in _ensureSpeechRecognition().

Closes #5483

static/boot.js

@@ -930,6 +930,7 @@ function _micToastKeyForRecognitionError(error){
     }
     if(recognition && !_forceMediaRecorder && !_rawAudioMode){
       _activeCaptureMode='speech';
+      recognition.lang=(typeof _locale!=='undefined'&&_locale._speech)||'en-US';
       recognition.start();
       _setRecording(true);
       return;