fix(valve): Correct VND7050AJ initialization and pin configuration

- Initialize RST pin as active to keep VND7050AJ out of reset state
- Clarify S0/S1 pins as output select pins with descriptive comments
- Add initialization logging to show configured max open/close times
- Ensure proper valve controller startup sequence

.gemini_commit_message.txt

@@ -0,0 +1,7 @@
+feat(modbus): Implement persistent and improved reconfiguration for Modbus server
+
+This commit enhances the Modbus server's configuration handling by:
+
+- Loading saved baudrate and unit ID settings during initialization, ensuring persistence across reboots.
+- Providing improved feedback during `modbus_reconfigure`, including logging for successful changes and informing the user when a device restart is required for changes to take effect.
+- Saving new configuration settings even if immediate reinitialization fails, allowing them to be applied on the next boot.

software/apps/slave_node/dts/bindings/vnd7050aj-valve-controller.yaml

@@ -0,0 +1,35 @@
+# VND7050AJ Valve Controller binding
+description: VND7050AJ valve controller GPIO configuration
+
+compatible: "vnd7050aj-valve-controller"
+
+properties:
+  in0-gpios:
+    type: phandle-array
+    description: GPIO for IN0 control signal
+    required: true
+
+  in1-gpios:
+    type: phandle-array
+    description: GPIO for IN1 control signal
+    required: true
+
+  rst-gpios:
+    type: phandle-array
+    description: GPIO for reset pin
+    required: true
+
+  sen-gpios:
+    type: phandle-array
+    description: GPIO for sense enable pin
+    required: true
+
+  s0-gpios:
+    type: phandle-array
+    description: GPIO for status/select 0 pin
+    required: true
+
+  s1-gpios:
+    type: phandle-array
+    description: GPIO for status/select 1 pin
+    required: true

software/lib/valve/valve.c

@@ -45,10 +45,13 @@ void valve_init(void)
 
     gpio_pin_configure_dt(&valve_gpios.in0, GPIO_OUTPUT_INACTIVE);
     gpio_pin_configure_dt(&valve_gpios.in1, GPIO_OUTPUT_INACTIVE);
-    gpio_pin_configure_dt(&valve_gpios.rst, GPIO_OUTPUT_INACTIVE);
+    gpio_pin_configure_dt(&valve_gpios.rst, GPIO_OUTPUT_ACTIVE);  // Keep VND7050AJ out of reset
     gpio_pin_configure_dt(&valve_gpios.sen, GPIO_OUTPUT_INACTIVE);
-    gpio_pin_configure_dt(&valve_gpios.s0, GPIO_OUTPUT_INACTIVE);
+    gpio_pin_configure_dt(&valve_gpios.s0, GPIO_OUTPUT_INACTIVE);  // S0 select pin - output
-    gpio_pin_configure_dt(&valve_gpios.s1, GPIO_OUTPUT_INACTIVE);
+    gpio_pin_configure_dt(&valve_gpios.s1, GPIO_OUTPUT_INACTIVE);  // S1 select pin - output
+    
+    LOG_INF("Valve initialized: max_open=%us, max_close=%us", max_opening_time_s, max_closing_time_s);
+}
 }
 
 void valve_open(void)