feat: button handler with press detection and combo support

Co-authored-by: Cursor <cursoragent@cursor.com>

src/main.cpp

@@ -4,10 +4,12 @@
 #include "settings.h"
 #include "wifi_manager.h"
 #include "power_manager.h"
+#include "button_handler.h"
 
 SettingsManager settingsManager;
 WiFiManager wifiManager;
 PowerManager powerManager;
+ButtonHandler buttonHandler;
 
 void setup() {
     auto cfg = M5.config();
@@ -19,15 +21,37 @@ void setup() {
     powerManager.begin();
     settingsManager.begin();
     wifiManager.begin(settingsManager);
+    buttonHandler.begin(powerManager, settingsManager);
 
-    Serial.printf("[main] Battery: %d%%, Charging: %s\n",
-                  powerManager.getBatteryPercent(),
-                  powerManager.isCharging() ? "yes" : "no");
     Serial.println("[main] Boot complete");
 }
 
 void loop() {
     M5.update();
     powerManager.updateBatteryLED();
-    delay(1000);
+
+    ButtonEvent event = buttonHandler.poll();
+    switch (event) {
+        case ButtonEvent::NextPhoto:
+            Serial.println("[main] → Next photo requested");
+            break;
+        case ButtonEvent::RandomPhoto:
+            Serial.println("[main] → Random photo requested");
+            break;
+        case ButtonEvent::PlayPause:
+            Serial.println("[main] → Play/Pause toggled");
+            break;
+        case ButtonEvent::DeepSleep:
+        case ButtonEvent::FactoryReset:
+            break;  // Handled internally
+        case ButtonEvent::None:
+            break;
+        default: {
+            ButtonEvent unreachable = event;
+            (void)unreachable;
+            break;
+        }
+    }
+
+    delay(10);  // 100Hz poll rate for responsive buttons
 }