Add run limit feature for relay channels with NVS support

- Introduced configuration options for enabling run limits in Kconfig.
- Added APIs to get and set run limits for individual relay channels.
- Implemented run limit timer functionality to automatically stop channels.
- Updated NVS handling to store and retrieve run limit values.
- Enhanced documentation in README and code comments to reflect new feature.

Closes #1080

src/relay_chn_ctl_single.c

@@ -4,11 +4,17 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include "esp_check.h"
 #include "relay_chn_priv_types.h"
 #include "relay_chn_core.h"
 #include "relay_chn_ctl.h"
 #include "relay_chn_output.h"
 
+#if RELAY_CHN_ENABLE_NVS == 1
+#include "relay_chn_nvs.h"
+#endif
+
+static const char *TAG = "RELAY_CHN_CTL";
 
 static relay_chn_ctl_t chn_ctl;
 
@@ -21,6 +27,20 @@ esp_err_t relay_chn_ctl_init(relay_chn_output_t *output, relay_chn_run_info_t *r
     chn_ctl.pending_cmd = RELAY_CHN_CMD_NONE;
     chn_ctl.output = output;
     chn_ctl.run_info = run_info;
+#if RELAY_CHN_ENABLE_RUN_LIMIT == 1
+    uint16_t run_limit_sec = RELAY_CHN_RUN_LIMIT_DEFAULT_SEC;
+    esp_err_t ret;
+#if RELAY_CHN_ENABLE_NVS == 1
+    // Load run limit value from NVS
+    ret = relay_chn_nvs_get_run_limit(chn_ctl.id, &run_limit_sec);
+    if (ret != ESP_OK && ret != ESP_ERR_NVS_NOT_FOUND) {
+        ESP_LOGE(TAG, "Failed to load run limit from NVS with error: %s", esp_err_to_name(ret));
+    }
+#endif
+    chn_ctl.run_limit_sec = run_limit_sec;
+    ret = relay_chn_init_run_limit_timer(&chn_ctl);
+    ESP_RETURN_ON_ERROR(ret, TAG, "Failed to initialize run limit timer");
+#endif
     return relay_chn_init_timer(&chn_ctl); // Create direction change inertia timer
 }
 
@@ -31,6 +51,12 @@ void relay_chn_ctl_deinit()
         esp_timer_delete(chn_ctl.inertia_timer);
         chn_ctl.inertia_timer = NULL;
     }
+#if RELAY_CHN_ENABLE_RUN_LIMIT == 1
+    if (chn_ctl.run_limit_timer != NULL) {
+        esp_timer_delete(chn_ctl.run_limit_timer);
+        chn_ctl.run_limit_timer = NULL;
+    }
+#endif
 }
 
 /* relay_chn APIs */
@@ -68,6 +94,28 @@ relay_chn_direction_t relay_chn_ctl_get_direction()
 {
     return relay_chn_output_get_direction(chn_ctl.output);
 }
+
+#if RELAY_CHN_ENABLE_RUN_LIMIT == 1
+uint16_t relay_chn_ctl_get_run_limit()
+{
+    return chn_ctl.run_limit_sec;
+}
+
+void relay_chn_ctl_set_run_limit(uint16_t time_sec)
+{
+    // Check for boundaries
+    if (time_sec > RELAY_CHN_RUN_LIMIT_MAX_SEC)
+        time_sec = RELAY_CHN_RUN_LIMIT_MAX_SEC;
+    else if (time_sec < RELAY_CHN_RUN_LIMIT_MIN_SEC)
+        time_sec = RELAY_CHN_RUN_LIMIT_MIN_SEC;
+    
+    chn_ctl.run_limit_sec = time_sec;
+
+#if RELAY_CHN_ENABLE_NVS == 1
+    relay_chn_nvs_set_run_limit(chn_ctl.id, time_sec);
+#endif
+} 
+#endif
 /* relay_chn APIs */
 
 relay_chn_ctl_t *relay_chn_ctl_get()