Rename power.h to Power.h for casing consistency with Power.cpp (#10919)

Every other .cpp/.h pair in src/ (350 of 351) uses identical
capitalization between the two files. Power.cpp/power.h was the sole
outlier; this aligns it with the rest of the codebase. No functional
change — all includes already resolved this file the same way on
case-sensitive filesystems.

Assisted-by: Claude Sonnet 5 <noreply@anthropic.com>

Signed-off-by: Andrew Yong <me@ndoo.sg>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/platform/nrf52/main-nrf52.cpp

@@ -19,11 +19,11 @@
 // #include <Adafruit_USBD_Device.h>
 #include "HardwareRNG.h"
 #include "NodeDB.h"
+#include "Power.h"
 #include "PowerMon.h"
 #include "error.h"
 #include "main.h"
 #include "meshUtils.h"
-#include "power.h"
 #include <power/PowerHAL.h>
 
 #include "Nrf52SaadcLock.h"