fix: health reachable_nodes uses alive filter, cluster status includes self in node_count

- handle_health: use all_members() filtered to Alive state instead of
  members() which returned 0 when nodes were in Suspect state
- handle_cluster_status: add +1 for self since members map excludes local node

crates/stemedb-cluster/src/gateway/handlers/query_handlers.rs

@@ -7,6 +7,7 @@ use std::sync::Arc;
 use tracing::instrument;
 
 use crate::gateway::service::GatewayState;
+use crate::membership::NodeState;
 use crate::sharding::ShardId;
 
 use super::types::{ApiError, ClusterStatusResponse, HealthResponse, NodeStatusInfo, QueryParams};
@@ -90,10 +91,15 @@ pub async fn handle_query(
 /// GET /v1/health - Health check.
 #[instrument(skip(state))]
 pub async fn handle_health(State(state): State<Arc<GatewayState>>) -> Json<HealthResponse> {
-    let members = state.membership.members();
+    let all_members = state.membership.all_members();
+    let alive_count = all_members.iter().filter(|(_, s)| *s == NodeState::Alive).count();
     let joined = state.membership.is_joined();
 
-    Json(HealthResponse { healthy: joined, reachable_nodes: members.len(), joined })
+    Json(HealthResponse {
+        healthy: joined && alive_count > 0,
+        reachable_nodes: alive_count,
+        joined,
+    })
 }
 
 /// GET /v1/cluster/status - Cluster status.
@@ -112,8 +118,9 @@ pub async fn handle_cluster_status(
         })
         .collect();
 
+    // +1 for self (members map excludes the local node)
     Json(ClusterStatusResponse {
-        node_count: all_members.len(),
+        node_count: all_members.len() + 1,
         shard_count: meta.num_shards() as u32,
         meta_version: meta.version,
         nodes,