Fix palette: entries 121-127 now visible (was black). Remove local flash.

src/app_task.cpp

@@ -130,24 +130,11 @@ void AppTask::process_switch_event(uint8_t switch_id, bool pressed) {
         if (pad_mapping[i].physical_switch == switch_id) {
             uint8_t channel = pad_mapping[i].midi_channel;
             uint8_t cc_num = cc_map[i];
-            // Use palette index 21 (yellow) so feedback is visible
-            uint8_t value = pressed ? 21 : 0;
+            // Use palette index 127 (magenta) for visible feedback
+            uint8_t value = pressed ? 127 : 0;
             
             if (pressed) {
                 midi_transport->send_cc(channel, cc_num, value);
-                led_driver->set_led_state(
-                    pad_mapping[i].midi_note,
-                    pad_mapping[i].midi_channel,
-                    value,
-                    i
-                );
-            } else {
-                led_driver->set_led_state(
-                    pad_mapping[i].midi_note,
-                    pad_mapping[i].midi_channel,
-                    0,
-                    i
-                );
             }
             
             Serial.printf("[APP] Switch %d -> Ch%d CC%d Val%d (%s)\n",