feat(app): Integrate application versioning

This commit introduces application versioning, exposing version information through the Modbus server and logging it at startup.

- Add  to provide version information
- Update  to log the application version at startup
- Update  to expose firmware version via Modbus
- Add file association for  in

software/lib/modbus_server/modbus_server.c

@@ -8,6 +8,7 @@
 #include <lib/modbus_server.h>
 #include <lib/valve.h>
 #include <lib/fwu.h>
+#include <app_version.h>
 
 #include <zephyr/usb/usb_device.h>
 
@@ -135,10 +136,10 @@ static int input_reg_rd(uint16_t addr, uint16_t *reg)
 		*reg = fwu_get_last_chunk_crc();
 		break;
 	case REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR:
-		*reg = (0 << 8) | 0;
+		*reg = (APP_VERSION_MAJOR << 8) | APP_VERSION_MINOR;
 		break;
 	case REG_INPUT_FIRMWARE_VERSION_PATCH:
-		*reg = 2;
+		*reg = APP_PATCHLEVEL;
 		break;
 	default:
 		*reg = 0;

software/lib/valve/valve.c

@@ -52,7 +52,6 @@ void valve_init(void)
     
     LOG_INF("Valve initialized: max_open=%us, max_close=%us", max_opening_time_s, max_closing_time_s);
 }
-}
 
 void valve_open(void)
 {