Add x25519_pubkey field to ValidatorInfo and ValidatorResponse

Prepares for X25519-based API key encryption where validators
publish their X25519 public key derived from sr25519 seed

Author: echobt

crates/core/src/types.rs

@@ -132,6 +132,9 @@ pub struct ValidatorInfo {
     pub is_active: bool,
     pub last_seen: chrono::DateTime<chrono::Utc>,
     pub peer_id: Option<String>,
+    /// X25519 public key for API key encryption (hex, 32 bytes)
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub x25519_pubkey: Option<String>,
 }
 
 impl ValidatorInfo {
@@ -142,6 +145,7 @@ impl ValidatorInfo {
             is_active: true,
             last_seen: chrono::Utc::now(),
             peer_id: None,
+            x25519_pubkey: None,
         }
     }
 }

crates/rpc-server/src/handlers.rs

@@ -97,6 +97,7 @@ pub async fn validators_handler(
             is_active: v.is_active,
             last_seen: v.last_seen,
             peer_id: v.peer_id.clone(),
+            x25519_pubkey: v.x25519_pubkey.clone(),
         })
         .collect();
 
@@ -389,6 +390,7 @@ pub async fn sync_handler(State(state): State<Arc<RpcState>>) -> Json<RpcRespons
             is_active: v.is_active,
             last_seen: v.last_seen,
             peer_id: v.peer_id.clone(),
+            x25519_pubkey: v.x25519_pubkey.clone(),
         })
         .collect();
 

crates/rpc-server/src/types.rs

@@ -63,6 +63,10 @@ pub struct ValidatorResponse {
     pub is_active: bool,
     pub last_seen: DateTime<Utc>,
     pub peer_id: Option<String>,
+    /// X25519 public key for API key encryption (hex, 32 bytes)
+    /// Derived from validator's sr25519 seed
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub x25519_pubkey: Option<String>,
 }
 
 /// Challenge info for RPC