feat(vscode-ide-companion): improve message handling and diff auto-opening

- Ignore messages during checkpoint saves in WebViewProvider
- Move diff auto-opening logic from useEffect to useWebViewMessages hook
- Remove unused imports and variables in EditToolCall component
- Enhance tool call handling for edit operations with diff content

packages/vscode-ide-companion/src/webview/WebViewProvider.ts

@@ -57,6 +57,20 @@ export class WebViewProvider {
     });
 
     // Setup agent callbacks
+    this.agentManager.onMessage((message) => {
+      // Ignore history replay while background /chat save is running
+      if (this.messageHandler.getIsSavingCheckpoint()) {
+        console.log(
+          '[WebViewProvider] Ignoring message during checkpoint save',
+        );
+        return;
+      }
+      this.sendMessageToWebView({
+        type: 'message',
+        data: message,
+      });
+    });
+
     this.agentManager.onStreamChunk((chunk: string) => {
       // Ignore stream chunks from background /chat save commands
       if (this.messageHandler.getIsSavingCheckpoint()) {

packages/vscode-ide-companion/src/webview/components/messages/toolcalls/Edit/EditToolCall.tsx

@@ -6,7 +6,7 @@
  * Edit tool call component - specialized for file editing operations
  */
 
-import { useEffect, useCallback, useMemo } from 'react';
+import { useMemo } from 'react';
 import type { BaseToolCallProps } from '../shared/types.js';
 import {
   groupContent,
@@ -14,8 +14,6 @@ import {
 } from '../shared/utils.js';
 import { FileLink } from '../../../layout/FileLink.js';
 import type { ToolCallContainerProps } from '../shared/LayoutComponents.js';
-import { useVSCode } from '../../../../hooks/useVSCode.js';
-import { handleOpenDiff } from '../../../../utils/diffUtils.js';
 
 export const ToolCallContainer: React.FC<ToolCallContainerProps> = ({
   label,
@@ -70,44 +68,9 @@ const getDiffSummary = (
  */
 export const EditToolCall: React.FC<BaseToolCallProps> = ({ toolCall }) => {
   const { content, locations, toolCallId } = toolCall;
-  const vscode = useVSCode();
 
   // Group content by type; memoize to avoid new array identities on every render
   const { errors, diffs } = useMemo(() => groupContent(content), [content]);
-  const handleOpenDiffInternal = useCallback(
-    (
-      path: string | undefined,
-      oldText: string | null | undefined,
-      newText: string | undefined,
-    ) => {
-      handleOpenDiff(vscode, path, oldText, newText);
-    },
-    [vscode],
-  );
-
-  // Automatically trigger openDiff when diff content is detected
-  // Only trigger once per tool call by checking toolCallId
-  useEffect(() => {
-    // Only auto-open if there are diffs and we have the required data
-    if (diffs.length > 0) {
-      const firstDiff = diffs[0];
-      const path = firstDiff.path || (locations && locations[0]?.path) || '';
-
-      if (
-        path &&
-        firstDiff.oldText !== undefined &&
-        firstDiff.newText !== undefined
-      ) {
-        // Add a small delay to ensure the component is fully rendered
-        const timer = setTimeout(() => {
-          handleOpenDiffInternal(path, firstDiff.oldText, firstDiff.newText);
-        }, 100);
-        // Proper cleanup function
-        return () => timer && clearTimeout(timer);
-      }
-    }
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [toolCallId]);
 
   // Failed case: show explicit failed message and render inline diffs
   if (toolCall.status === 'failed') {

packages/vscode-ide-companion/src/webview/hooks/useWebViewMessages.ts

@@ -386,7 +386,7 @@ export const useWebViewMessages = ({
 
           if (permToolCall?.toolCallId) {
             // Infer kind more robustly for permission preview:
-            // - If content contains a diff entry, force 'edit' so the EditToolCall auto-opens VS Code diff
+            // - If content contains a diff entry, force 'edit' so the EditToolCall can handle it properly
             // - Else try title-based hints; fall back to provided kind or 'execute'
             let kind = permToolCall.kind || 'execute';
             const contentArr = (permToolCall.content as unknown[]) || [];
@@ -400,6 +400,32 @@ export const useWebViewMessages = ({
               : false;
             if (hasDiff) {
               kind = 'edit';
+
+              // Auto-open diff view for edit operations with diff content
+              // This replaces the useEffect auto-trigger in EditToolCall component
+              const diffContent = contentArr.find(
+                (c: unknown) =>
+                  !!c &&
+                  typeof c === 'object' &&
+                  (c as { type?: string }).type === 'diff',
+              ) as
+                | { path?: string; oldText?: string; newText?: string }
+                | undefined;
+
+              if (
+                diffContent?.path &&
+                diffContent?.oldText !== undefined &&
+                diffContent?.newText !== undefined
+              ) {
+                vscode.postMessage({
+                  type: 'openDiff',
+                  data: {
+                    path: diffContent.path,
+                    oldText: diffContent.oldText,
+                    newText: diffContent.newText,
+                  },
+                });
+              }
             } else if (permToolCall.title) {
               const title = permToolCall.title.toLowerCase();
               if (title.includes('touch') || title.includes('echo')) {