chore: remove core fixes from validation PR

The core fixes (scheduler hang, policy visibility) have been moved to a standalone PR to ensure atomicity. This PR now focuses exclusively on the testing infrastructure and documentation.

packages/cli/src/ui/components/messages/ToolGroupMessage.tsx

@@ -21,7 +21,6 @@ import { isShellTool } from './ToolShared.js';
 import {
   shouldHideToolCall,
   CoreToolCallStatus,
-  ToolErrorType,
 } from '@google/gemini-cli-core';
 import { useUIState } from '../../contexts/UIStateContext.js';
 import { getToolGroupBorderAppearance } from '../../utils/borderStyles.js';
@@ -60,8 +59,7 @@ export const ToolGroupMessage: React.FC<ToolGroupMessageProps> = ({
         if (
           isLowErrorVerbosity &&
           t.status === CoreToolCallStatus.Error &&
-          !t.isClientInitiated &&
-          t.errorType !== ToolErrorType.POLICY_VIOLATION
+          !t.isClientInitiated
         ) {
           return false;
         }

packages/cli/src/ui/hooks/toolMapping.ts

@@ -10,7 +10,6 @@ import {
   type ToolResultDisplay,
   debugLogger,
   CoreToolCallStatus,
-  type ToolErrorType,
 } from '@google/gemini-cli-core';
 import {
   type HistoryItemToolGroup,
@@ -64,7 +63,6 @@ export function mapToDisplay(
     let progressMessage: string | undefined = undefined;
     let progress: number | undefined = undefined;
     let progressTotal: number | undefined = undefined;
-    let errorType: ToolErrorType | undefined = undefined;
 
     switch (call.status) {
       case CoreToolCallStatus.Success:
@@ -74,7 +72,6 @@ export function mapToDisplay(
       case CoreToolCallStatus.Error:
       case CoreToolCallStatus.Cancelled:
         resultDisplay = call.response.resultDisplay;
-        errorType = call.response.errorType;
         break;
       case CoreToolCallStatus.AwaitingApproval:
         correlationId = call.correlationId;
@@ -117,7 +114,6 @@ export function mapToDisplay(
       progressTotal,
       approvalMode: call.approvalMode,
       originalRequestName: call.request.originalRequestName,
-      errorType,
     };
   });
 

packages/cli/src/ui/types.ts

@@ -16,7 +16,6 @@ import {
   type AgentDefinition,
   type ApprovalMode,
   type Kind,
-  type ToolErrorType,
   CoreToolCallStatus,
   checkExhaustive,
 } from '@google/gemini-cli-core';
@@ -118,7 +117,6 @@ export interface IndividualToolCallDisplay {
   originalRequestName?: string;
   progress?: number;
   progressTotal?: number;
-  errorType?: ToolErrorType;
 }
 
 export interface CompressionProps {

packages/core/src/confirmation-bus/message-bus.ts

@@ -11,7 +11,6 @@ import { PolicyDecision } from '../policy/types.js';
 import { MessageBusType, type Message } from './types.js';
 import { safeJsonStringify } from '../utils/safeJsonStringify.js';
 import { debugLogger } from '../utils/debugLogger.js';
-import { coreEvents } from '../utils/events.js';
 
 export class MessageBus extends EventEmitter {
   constructor(
@@ -71,10 +70,6 @@ export class MessageBus extends EventEmitter {
             break;
           case PolicyDecision.DENY:
             // Emit both rejection and response messages
-            coreEvents.emitFeedback(
-              'error',
-              `Tool call "${message.toolCall.name}" was blocked by policy.`,
-            );
             this.emitMessage({
               type: MessageBusType.TOOL_POLICY_REJECTION,
               toolCall: message.toolCall,

packages/core/src/scheduler/scheduler.ts

@@ -35,7 +35,11 @@ import { runInDevTraceSpan } from '../telemetry/trace.js';
 import { logToolCall } from '../telemetry/loggers.js';
 import { ToolCallEvent } from '../telemetry/types.js';
 import type { EditorType } from '../utils/editor.js';
-import { type SerializableConfirmationDetails } from '../confirmation-bus/types.js';
+import {
+  MessageBusType,
+  type SerializableConfirmationDetails,
+  type ToolConfirmationRequest,
+} from '../confirmation-bus/types.js';
 import { runWithToolCallContext } from '../utils/toolCallContext.js';
 import {
   coreEvents,
@@ -87,6 +91,9 @@ const createErrorResponse = (
  * Coordinates execution via state updates and event listening.
  */
 export class Scheduler {
+  // Tracks which MessageBus instances have the legacy listener attached to prevent duplicates.
+  private static subscribedMessageBuses = new WeakSet<MessageBus>();
+
   private readonly state: SchedulerStateManager;
   private readonly executor: ToolExecutor;
   private readonly modifier: ToolModificationHandler;
@@ -120,6 +127,8 @@ export class Scheduler {
     this.executor = new ToolExecutor(this.context);
     this.modifier = new ToolModificationHandler();
 
+    this.setupMessageBusListener(this.messageBus);
+
     coreEvents.on(CoreEvent.McpProgress, this.handleMcpProgress);
   }
 
@@ -152,6 +161,28 @@ export class Scheduler {
     });
   };
 
+  private setupMessageBusListener(messageBus: MessageBus): void {
+    if (Scheduler.subscribedMessageBuses.has(messageBus)) {
+      return;
+    }
+
+    // TODO: Optimize policy checks. Currently, tools check policy via
+    // MessageBus even though the Scheduler already checked it.
+    messageBus.subscribe(
+      MessageBusType.TOOL_CONFIRMATION_REQUEST,
+      async (request: ToolConfirmationRequest) => {
+        await messageBus.publish({
+          type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+          correlationId: request.correlationId,
+          confirmed: false,
+          requiresUserConfirmation: true,
+        });
+      },
+    );
+
+    Scheduler.subscribedMessageBuses.add(messageBus);
+  }
+
   /**
    * Schedules a batch of tool calls.
    * @returns A promise that resolves with the results of the completed batch.