fix: persist watchdog_enabled setting from runtime_settings.json

The watchdog_enabled setting was not being applied from the
runtime_settings.json file because the code was checking if
WatchDogIdle or WatchDogBusy were set via env vars, but not
checking if WatchDog itself was set via env vars.

This caused the setting to be ignored when the user enabled
watchdog through the UI because:
1. The file was written correctly with watchdog_enabled=true
2. But on reload, the code checked !envWatchdogIdle && !envWatchdogBusy
3. This condition didn't account for the main WatchDog flag
4. So the setting from file was never applied

Fix:
- Add envWatchdog check to track if WatchDog was set via env var
- Apply WatchdogEnabled from file when not set via env
- Also disable WatchDogIdle and WatchDogBusy when watchdog is disabled

Fixes #9125

Author: Team Coding Agent 1

core/application/config_file_watcher.go

@@ -197,6 +197,7 @@ func readRuntimeSettingsJson(startupAppConfig config.ApplicationConfig) fileHand
 		envWatchdogBusy := appConfig.WatchDogBusy == startupAppConfig.WatchDogBusy
 		envWatchdogIdleTimeout := appConfig.WatchDogIdleTimeout == startupAppConfig.WatchDogIdleTimeout
 		envWatchdogBusyTimeout := appConfig.WatchDogBusyTimeout == startupAppConfig.WatchDogBusyTimeout
+		envWatchdog := appConfig.WatchDog == startupAppConfig.WatchDog
 		envSingleBackend := appConfig.SingleBackend == startupAppConfig.SingleBackend
 		envMaxActiveBackends := appConfig.MaxActiveBackends == startupAppConfig.MaxActiveBackends
 		envParallelRequests := appConfig.ParallelBackendRequests == startupAppConfig.ParallelBackendRequests
@@ -352,10 +353,12 @@ func readRuntimeSettingsJson(startupAppConfig config.ApplicationConfig) fileHand
 				appConfig.AgentJobRetentionDays = *settings.AgentJobRetentionDays
 			}
 
-			// If watchdog is enabled via file but not via env, ensure WatchDog flag is set
-			if !envWatchdogIdle && !envWatchdogBusy {
-				if settings.WatchdogEnabled != nil && *settings.WatchdogEnabled {
-					appConfig.WatchDog = true
+			if settings.WatchdogEnabled != nil && !envWatchdog {
+				appConfig.WatchDog = *settings.WatchdogEnabled
+				// If watchdog is being disabled, also disable the sub-features
+				if !appConfig.WatchDog {
+					appConfig.WatchDogIdle = false
+					appConfig.WatchDogBusy = false
 				}
 			}
 		}