Add Transmit history persistence for respecting traffic intervals between reboots (#9748)

* Add transmit history for throttling that persists between reboots

* Fix RAK long press detection to prevent phantom shutdowns from floating pins

* Update test/test_transmit_history/test_main.cpp

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Test fixes and placeholder for content handler tests

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

src/sleep.cpp

@@ -9,6 +9,7 @@
 #include "MeshService.h"
 #include "NodeDB.h"
 #include "PowerMon.h"
+#include "TransmitHistory.h"
 #include "detect/LoRaRadioType.h"
 #include "error.h"
 #include "main.h"
@@ -245,6 +246,10 @@ void doDeepSleep(uint32_t msecToWake, bool skipPreflight = false, bool skipSaveN
         nodeDB->saveToDisk();
     }
 
+    // Persist broadcast transmit times so throttle survives reboot
+    if (transmitHistory)
+        transmitHistory->saveToDisk();
+
 #ifdef PIN_POWER_EN
     digitalWrite(PIN_POWER_EN, LOW);
     pinMode(PIN_POWER_EN, INPUT); // power off peripherals