Add triple-tap lights-off and fix LED pin to D5

- Triple tap turns off LEDs; any subsequent tap or hold resumes the current show
- Change LED_DATA_PIN default from 6 to 5 across config, docs, and wiring diagram
- Fix Makefile upload to pass --input-dir so it uses the pre-built binary

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

arduino/cosplay_lights/cosplay_lights.ino

@@ -5,6 +5,7 @@
  * A single button navigates between shows:
  *   1 tap  — next show
  *   2 taps — previous show
+ *   3 taps — lights off (any tap or hold resumes)
  *   hold   — reset to show 0 (blue breath)
  *
  * To add or update shows:
@@ -28,8 +29,10 @@ static ShowDef  s_show;                       // PROGMEM cache for the active sh
 static uint16_t s_step_index  = 0;
 static uint32_t s_step_start  = 0;
 static CRGB     s_from_color  = CRGB::Black;
+static bool     s_lights_off  = false;
 
 static void load_show(uint8_t index) {
+    s_lights_off = false;
     s_show_index = index;
     s_show       = read_show_def(&SHOWS[index]);
     s_step_index = 0;
@@ -76,6 +79,7 @@ void setup() {
     s_button.setPressMs(800);
     s_button.attachClick([]()          { load_show((s_show_index + 1) % SHOW_COUNT); });
     s_button.attachDoubleClick([]()    { load_show((s_show_index + SHOW_COUNT - 1) % SHOW_COUNT); });
+    s_button.attachMultiClick([]()     { if (s_button.getNumberClicks() == 3) { s_lights_off = true; leds_apply_color(CRGB::Black); leds_show(); } });
     s_button.attachLongPressStart([]() { load_show(0); });
 }
 
@@ -87,6 +91,8 @@ void loop() {
     if (now - s_last_frame < 16) return;
     s_last_frame = now;
 
+    if (s_lights_off) return;
+
     Step    step = read_step(&s_show.steps[s_step_index]);
     CRGB    to   = CRGB(step.r, step.g, step.b);
     uint8_t t8   = step_progress(step, now);