MG24 entropy/filesystem fixes

zephcore/boards/common/mg24_common.conf

@@ -24,3 +24,14 @@ CONFIG_ASSERT=y
 # ========== Heap ==========
 # Silabs BLE stack requires larger heap (override zephcore_common 2KB default)
 CONFIG_HEAP_MEM_POOL_SIZE=32768
+
+# ========== Storage ==========
+# BLE bonds via file-based settings on LittleFS (same as nRF52)
+CONFIG_NVS=n
+CONFIG_SETTINGS_NVS=n
+CONFIG_SETTINGS_FILE=y
+CONFIG_SETTINGS_FILE_PATH="/lfs/settings"
+
+# ========== ADC ==========
+# No battery voltage divider on MG24 boards — disable ADC driver
+CONFIG_ADC=n

zephcore/boards/mg24/xiao_mg24/board.overlay

@@ -29,6 +29,11 @@
 	/delete-node/ zephyr,user;
 };
 
+/* Enable SEMAILBOX — hardware crypto + TRNG (entropy source for mbedTLS/BLE) */
+&se {
+	status = "okay";
+};
+
 /* Disable I2C0 — default pins PC4(SCL)/PC5(SDA) conflict with NSS/RXEN */
 &i2c0 {
 	status = "disabled";