Simplify service recovery notification logic

- Remove bloated last_meaningful_status tracking
- Treat any Unknown→Ok transition as recovery
- Reduce JSON persistence to only metric_statuses and metric_details
- Eliminate unnecessary status history complexity

agent/src/notifications/mod.rs

@@ -73,6 +73,7 @@ impl NotificationManager {
             .copied()
             .unwrap_or(Status::Unknown);
 
+
         // Check if status actually changed
         if old_status != new_status {
             // Update stored status only on change
@@ -114,7 +115,7 @@ impl NotificationManager {
         // Only notify on transitions to warning/critical, or recovery to ok
         let should_send = match (status_change.old_status, status_change.new_status) {
             (_, Status::Warning) | (_, Status::Critical) => true,
-            (Status::Warning | Status::Critical, Status::Ok) => true,
+            (Status::Warning | Status::Critical | Status::Unknown, Status::Ok) => true,
             _ => false,
         };
 
@@ -136,8 +137,9 @@ impl NotificationManager {
         status_change.details = Some(self.format_metric_details(metric));
 
         // For recovery notifications, include original problem details
-        if status_change.new_status == Status::Ok && 
-           (status_change.old_status == Status::Warning || status_change.old_status == Status::Critical) {
+        let is_recovery = status_change.new_status == Status::Ok;
+            
+        if is_recovery {
             if let Some(old_details) = self.metric_details.get(&status_change.metric_name) {
                 status_change.details = Some(format!(
                     "Recovered from: {}\nCurrent status: {}",