feat: Implement Trace management, add HITL support

a2a/src/main/java/com/google/adk/a2a/agent/RemoteA2AAgent.java

@@ -28,14 +28,14 @@
 import com.google.adk.agents.Callbacks;
 import com.google.adk.agents.InvocationContext;
 import com.google.adk.events.Event;
+import com.google.adk.utils.AgentEnums.AgentOrigin;
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.genai.types.Content;
 import com.google.genai.types.CustomMetadata;
 import com.google.genai.types.Part;
 import io.a2a.client.Client;
 import io.a2a.client.ClientEvent;
-import io.a2a.client.MessageEvent;
 import io.a2a.client.TaskEvent;
 import io.a2a.client.TaskUpdateEvent;
 import io.a2a.spec.A2AClientException;
@@ -541,6 +541,11 @@ protected Flowable<Event> runLiveImpl(InvocationContext invocationContext) {
         "runLiveImpl for " + getClass() + " via A2A is not implemented.");
   }
 
+  @Override
+  public AgentOrigin toolOrigin() {
+    return AgentOrigin.A2A;
+  }
+
   /** Exception thrown when the agent card cannot be resolved. */
   public static class AgentCardResolutionError extends RuntimeException {
     public AgentCardResolutionError(String message) {

core/src/main/java/com/google/adk/agents/BaseAgent.java

@@ -25,6 +25,7 @@
 import com.google.adk.events.Event;
 import com.google.adk.plugins.Plugin;
 import com.google.adk.telemetry.Tracing;
+import com.google.adk.utils.AgentEnums.AgentOrigin;
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.annotations.DoNotCall;
@@ -256,6 +257,15 @@ public ImmutableList<? extends AfterAgentCallback> afterAgentCallback() {
     return afterAgentCallback;
   }
 
+  /**
+   * Returns the origin of the tool when this agent is used as a tool.
+   *
+   * @return the tool origin, defaults to "BASE_AGENT".
+   */
+  public AgentOrigin toolOrigin() {
+    return AgentOrigin.BASE_AGENT;
+  }
+
   /**
    * The resolved beforeAgentCallback field as a list.
    *

core/src/main/java/com/google/adk/plugins/agentanalytics/BatchProcessor.java

@@ -147,7 +147,12 @@ public void flush() {
           } else {
             logger.fine("Successfully wrote " + batch.size() + " rows to BigQuery.");
           }
-        } catch (AppendSerializationError ase) {
+        }
+      } catch (Exception e) {
+        if (e instanceof InterruptedException) {
+          Thread.currentThread().interrupt();
+        }
+        if (e.getCause() instanceof AppendSerializationError ase) {
           logger.log(
               Level.SEVERE, "Failed to write batch to BigQuery due to serialization error", ase);
           Map<Integer, String> rowIndexToErrorMessage = ase.getRowIndexToErrorMessage();
@@ -161,12 +166,9 @@ public void flush() {
             logger.severe(
                 "AppendSerializationError occurred, but no row-specific errors were provided.");
           }
+        } else {
+          logger.log(Level.SEVERE, "Failed to write batch to BigQuery", e);
         }
-      } catch (Exception e) {
-        if (e instanceof InterruptedException) {
-          Thread.currentThread().interrupt();
-        }
-        logger.log(Level.SEVERE, "Failed to write batch to BigQuery", e);
       } finally {
         // Clear the vectors to release the memory.
         root.clear();
@@ -185,7 +187,12 @@ private void populateVector(FieldVector vector, int index, Object value) {
       return;
     }
     if (vector instanceof VarCharVector varCharVector) {
-      String strValue = (value instanceof JsonNode jsonNode) ? jsonNode.asText() : value.toString();
+      String strValue;
+      if (value instanceof JsonNode jsonNode) {
+        strValue = jsonNode.isTextual() ? jsonNode.asText() : jsonNode.toString();
+      } else {
+        strValue = value.toString();
+      }
       varCharVector.setSafe(index, strValue.getBytes(UTF_8));
     } else if (vector instanceof BigIntVector bigIntVector) {
       long longValue;