hbc proper termination, hbd config reloadable

hbd/server/threshold.py

@@ -316,6 +316,31 @@ class ThresholdChecker:
                 total_thresholds
             )
     
+    def reload(self, config: Dict[str, Any]):
+        """Reload threshold configuration from new config dict.
+        
+        This clears all existing thresholds and re-parses from the new configuration.
+        Alert states are preserved to maintain hysteresis across reloads.
+        
+        Args:
+            config: New configuration dictionary
+        """
+        logger.info("Reloading threshold configuration...")
+        
+        # Clear old configuration
+        self.threshold_configs.clear()
+        self.thresholds.clear()
+        self.host_config_mapping.clear()
+        
+        # Parse new configuration
+        self._parse_config(config)
+        
+        total_thresholds = sum(len(cfg) for cfg in self.threshold_configs.values())
+        if total_thresholds == 0 and len(self.thresholds) > 0:
+            total_thresholds = len(self.thresholds)
+        
+        logger.info("Threshold configuration reloaded: %d total thresholds", total_thresholds)
+    
     def _parse_config(self, config: Dict[str, Any]):
         """Parse threshold configuration from YAML structure.