feat(valve): Implement GPIO control for VND7050AJ

This commit implements the real valve control using the GPIOs connected to the VND7050AJ driver.

- The `weact_stm32g431_core.overlay` is updated with a specific compatible string and a device tree label for the valve controller.
- `valve.h` is extended to include GPIO device specifications.
- `valve.c` now initializes and controls the GPIOs for opening and closing the valve, including the reset logic. The IN0 and IN1 pins are interlocked to prevent simultaneous activation. The RST pin is activated before each movement and deactivated afterward.

This replaces the previous virtual/simulated valve logic with actual hardware control.

software/apps/slave_node/boards/weact_stm32g431_core.overlay

@@ -1,6 +1,6 @@
 / {
-    vnd7050aj {
-        compatible = "gpio-leds"; // Using generic GPIO compatible
+    vnd7050aj: vnd7050aj {
+        compatible = "vnd7050aj-valve-controller";
         status = "okay";
         
         // VND7050AJ GPIO pin definitions