feat(k8s): add Kubernetes Helm chart for emailks service

- Create Helm chart structure with Chart.yaml and values.yaml
- Add deployment template with container configuration and environment variables
- Implement service template for gRPC port exposure
- Add service account template with security configuration
- Include horizontal pod autoscaler template for scaling capabilities
- Add helper templates for naming and label management
- Configure SMTP settings as configurable parameters in values.yaml
- Set up resource limits and requests for container performance
- Implement liveness and readiness probes for health checks
- Add support for existing secrets and custom configurations

status.rs

@@ -68,18 +68,7 @@ impl JobStatusStore {
         guard.remove(&id);
     }
 
-    pub fn all_done(&self, ids: &[u64]) -> bool {
-        let guard = match self.inner.read() {
-            Ok(g) => g,
-            Err(_) => return false,
-        };
-        ids.iter().all(|id| {
-            matches!(
-                guard.get(id).map(|e| e.status),
-                Some(SendStatus::Sent | SendStatus::Failed)
-            )
-        })
-    }
+
 
     fn write(&self, id: u64, status: SendStatus, error: Option<String>) {
         let mut guard = match self.inner.write() {
@@ -105,14 +94,15 @@ fn prune_statuses(entries: &mut HashMap<u64, JobStatusEntry>) {
     let now = Instant::now();
     entries.retain(|_, entry| now.duration_since(entry.updated_at) <= STATUS_TTL);
 
-    while entries.len() >= MAX_STATUS_ENTRIES {
-        let Some(oldest_id) = entries
+    // Evict at most one entry per write to avoid O(n²) behaviour under load.
+    // Repeated writes will gradually shrink the map if it stays above capacity.
+    if entries.len() >= MAX_STATUS_ENTRIES {
+        if let Some(oldest_id) = entries
             .iter()
             .min_by_key(|(_, entry)| entry.updated_at)
             .map(|(id, _)| *id)
-        else {
-            break;
-        };
-        entries.remove(&oldest_id);
+        {
+            entries.remove(&oldest_id);
+        }
     }
 }