[QoS][Solana] Disqualify endpoints with recent non-JSONRPC response

proto/path/qos/jsonrpc_validation_error.proto

@@ -0,0 +1,24 @@
+syntax = "proto3";
+package path.qos;
+
+option go_package = "github.com/buildwithgrove/path/observation/qos";
+
+import "google/protobuf/timestamp.proto";
+
+// JsonRpcResponseValidationError captures validation errors for JSON-RPC responses
+message JsonRpcResponseValidationError {
+  // Type of validation error
+  JsonRpcValidationErrorType error_type = 1;
+
+  // Timestamp when the validation error occurred
+  google.protobuf.Timestamp timestamp = 2;
+}
+
+// Enum for different types of JSON-RPC validation errors
+enum JsonRpcValidationErrorType {
+  // Default/unspecified validation error
+  JSON_RPC_VALIDATION_ERROR_TYPE_UNSPECIFIED = 0;
+
+  // Response is not a valid JSON-RPC response
+  NON_JSONRPC_RESPONSE = 1;
+}

proto/path/qos/solana.proto

@@ -6,6 +6,7 @@ option go_package = "github.com/buildwithgrove/path/observation/qos";
 import "path/qos/jsonrpc.proto";
 import "path/qos/request_origin.proto";
 import "path/qos/request_error.proto";
+import "path/qos/jsonrpc_validation_error.proto";
 
 // SolanaRequestObservations captures QoS data for a single Solana blockchain service request,
 // including all observations made during potential retries.
@@ -79,4 +80,7 @@ message SolanaGetHealthResponse {
 // Examples: getTokenSupply, getTransaction
 message SolanaUnrecognizedResponse {
   JsonRpcResponse jsonrpc_response = 1;
-}
+
+  // Optional validation error information
+  optional JsonRpcResponseValidationError validation_error = 2;
+}