fix: kick-start fan on every 0→on transition

Previous kick-start only fired when duty < 200, but all level duties are
≥230, so L1 starts from rest at PWM 230 and the rotor can't break static
friction. Now we briefly drive 100% on any off→on transition before
dropping to the target duty.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

main/main.ino

@@ -55,16 +55,21 @@ int yOffset = 30;
 uint8_t fanLevel = 0;  // 0 = off, 1..NUM_LEVELS
 
 void applyFan() {
+  static uint8_t lastDuty = 0;
   if (fanLevel == 0) {
     ledcWrite(FAN_PIN, 0);
+    lastDuty = 0;
     return;
   }
   uint8_t duty = LEVELS[fanLevel - 1].duty;
-  if (duty > 0 && duty < 200) {
-    ledcWrite(FAN_PIN, 255);  // kick-start
-    delay(300);
+  // Kick-start whenever spinning up from stopped — full duty briefly so the
+  // rotor breaks static friction, then drop to the target.
+  if (lastDuty == 0) {
+    ledcWrite(FAN_PIN, 255);
+    delay(400);
   }
   ledcWrite(FAN_PIN, duty);
+  lastDuty = duty;
 }
 
 void publishFan() {