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

include/relay_chn_defs.h

@@ -15,6 +15,7 @@ extern "C" {
 #define RELAY_CHN_COUNT CONFIG_RELAY_CHN_COUNT
 #define RELAY_CHN_ENABLE_TILTING CONFIG_RELAY_CHN_ENABLE_TILTING
 #define RELAY_CHN_ENABLE_NVS CONFIG_RELAY_CHN_ENABLE_NVS
+#define RELAY_CHN_ENABLE_RUN_LIMIT CONFIG_RELAY_CHN_ENABLE_RUN_LIMIT
 
 #if RELAY_CHN_ENABLE_NVS == 1
 #define RELAY_CHN_NVS_NAMESPACE CONFIG_RELAY_CHN_NVS_NAMESPACE
@@ -28,6 +29,12 @@ extern "C" {
 #define RELAY_CHN_ID_ALL RELAY_CHN_COUNT /*!< Special ID to address all channels */
 #endif
 
+#if RELAY_CHN_ENABLE_RUN_LIMIT == 1
+#define RELAY_CHN_RUN_LIMIT_MIN_SEC CONFIG_RELAY_CHN_RUN_LIMIT_MIN_SEC
+#define RELAY_CHN_RUN_LIMIT_MAX_SEC CONFIG_RELAY_CHN_RUN_LIMIT_MAX_SEC
+#define RELAY_CHN_RUN_LIMIT_DEFAULT_SEC CONFIG_RELAY_CHN_RUN_LIMIT_DEFAULT_SEC
+#endif
+
 #ifdef __cplusplus
 }
 #endif