feat(power): add battery monitoring and status overlays

components/platform/internal/platform_battery_internal.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef enum {
+    PLATFORM_BATTERY_LOAD_AUDIO = 0,
+    PLATFORM_BATTERY_LOAD_STEPPER,
+    PLATFORM_BATTERY_LOAD_COUNT,
+} platform_battery_load_source_t;
+
+void platform_battery_load_begin(platform_battery_load_source_t source);
+void platform_battery_load_end(platform_battery_load_source_t source);