Adding loop function

arduino/cosplay_lights/cosplay_lights.ino

@@ -5,7 +5,7 @@
  * A single button navigates between shows:
  *   1 tap  — next show
  *   2 taps — previous show
- *   hold   — reset to show 0 (slow blue pulse)
+ *   hold   — reset to show 0 (blue breath)
  *
  * To add or update shows:
  *   1. Add or edit a .txt file in converter/shows/
@@ -66,10 +66,19 @@ static float step_progress(const Step& step) {
     return (t < 1.0f) ? t : 1.0f;
 }
 
-// Complete the current step and advance to the next (loops at end of show).
+// Complete the current step and advance to the next.
+// SHOW_LOOP wraps back to step 0; SHOW_SINGLE loads the next show when the last step ends.
 static void advance_step(CRGB reached_color) {
     s_from_color = reached_color;
-    s_step_index = (s_step_index + 1) % s_show.length;
+    uint16_t next = s_step_index + 1;
+    if (next >= s_show.length) {
+        if (s_show.mode == SHOW_SINGLE) {
+            load_show((s_show_index + 1) % SHOW_COUNT);
+            return;
+        }
+        next = 0;
+    }
+    s_step_index = next;
     s_step_start = millis();
 }
 
@@ -78,7 +87,7 @@ static void advance_step(CRGB reached_color) {
 void setup() {
     leds_begin();
     button_begin(BUTTON_PIN);
-    load_show(0);   // start on show 0 — slow blue pulse
+    load_show(0);   // start on show 0 — blue breath
 }
 
 void loop() {
@@ -93,7 +102,7 @@ void loop() {
         load_show((s_show_index + SHOW_COUNT - 1) % SHOW_COUNT);
     }
     if (evt == BTN_HOLD) {
-        // Reset to show 0 (blue pulse) from any position.
+        // Reset to show 0 (blue breath) from any position.
         load_show(0);
     }