diff --git a/packages/vscode-ide-companion/src/services/acpConnection.ts b/packages/vscode-ide-companion/src/services/acpConnection.ts
index f4c95948..464f8bcb 100644
--- a/packages/vscode-ide-companion/src/services/acpConnection.ts
+++ b/packages/vscode-ide-companion/src/services/acpConnection.ts
@@ -10,8 +10,8 @@ import type {
   AcpPermissionRequest,
   AcpResponse,
   AcpSessionUpdate,
-  ApprovalModeValue,
 } from '../types/acpTypes.js';
+import type { ApprovalModeValue } from '../types/approvalModeValueTypes.js';
 import type { ChildProcess, SpawnOptions } from 'child_process';
 import { spawn } from 'child_process';
 import type {
diff --git a/packages/vscode-ide-companion/src/services/acpSessionManager.ts b/packages/vscode-ide-companion/src/services/acpSessionManager.ts
index 8812282a..55b1d2b5 100644
--- a/packages/vscode-ide-companion/src/services/acpSessionManager.ts
+++ b/packages/vscode-ide-companion/src/services/acpSessionManager.ts
@@ -14,8 +14,8 @@ import type {
   AcpRequest,
   AcpNotification,
   AcpResponse,
-  ApprovalModeValue,
 } from '../types/acpTypes.js';
+import type { ApprovalModeValue } from '../types/approvalModeValueTypes.js';
 import { AGENT_METHODS } from '../constants/acpSchema.js';
 import type { PendingRequest } from '../types/connectionTypes.js';
 import type { ChildProcess } from 'child_process';
diff --git a/packages/vscode-ide-companion/src/services/qwenAgentManager.ts b/packages/vscode-ide-companion/src/services/qwenAgentManager.ts
index 5ddd5612..c3aa6525 100644
--- a/packages/vscode-ide-companion/src/services/qwenAgentManager.ts
+++ b/packages/vscode-ide-companion/src/services/qwenAgentManager.ts
@@ -7,8 +7,8 @@ import { AcpConnection } from './acpConnection.js';
 import type {
   AcpSessionUpdate,
   AcpPermissionRequest,
-  ApprovalModeValue,
 } from '../types/acpTypes.js';
+import type { ApprovalModeValue } from '../types/approvalModeValueTypes.js';
 import { QwenSessionReader, type QwenSession } from './qwenSessionReader.js';
 import { QwenSessionManager } from './qwenSessionManager.js';
 import type {
diff --git a/packages/vscode-ide-companion/src/services/qwenSessionUpdateHandler.ts b/packages/vscode-ide-companion/src/services/qwenSessionUpdateHandler.ts
index e27fbe67..d7b24bb2 100644
--- a/packages/vscode-ide-companion/src/services/qwenSessionUpdateHandler.ts
+++ b/packages/vscode-ide-companion/src/services/qwenSessionUpdateHandler.ts
@@ -10,7 +10,8 @@
  * Handles session updates from ACP and dispatches them to appropriate callbacks
  */
 
-import type { AcpSessionUpdate, ApprovalModeValue } from '../types/acpTypes.js';
+import type { AcpSessionUpdate } from '../types/acpTypes.js';
+import type { ApprovalModeValue } from '../types/approvalModeValueTypes.js';
 import type { QwenAgentCallbacks } from '../types/chatTypes.js';
 
 /**
diff --git a/packages/vscode-ide-companion/src/types/acpTypes.ts b/packages/vscode-ide-companion/src/types/acpTypes.ts
index 1fb4de17..252f3d5d 100644
--- a/packages/vscode-ide-companion/src/types/acpTypes.ts
+++ b/packages/vscode-ide-companion/src/types/acpTypes.ts
@@ -3,6 +3,7 @@
  * Copyright 2025 Qwen Team
  * SPDX-License-Identifier: Apache-2.0
  */
+import type { ApprovalModeValue } from './approvalModeValueTypes.js';
 
 export const JSONRPC_VERSION = '2.0' as const;
 export const authMethod = 'qwen-oauth';
@@ -138,8 +139,6 @@ export interface PlanUpdate extends BaseSessionUpdate {
   };
 }
 
-export type ApprovalModeValue = 'plan' | 'default' | 'auto-edit' | 'yolo';
-
 export {
   ApprovalMode,
   APPROVAL_MODE_MAP,
diff --git a/packages/vscode-ide-companion/src/types/approvalModeValueTypes.ts b/packages/vscode-ide-companion/src/types/approvalModeValueTypes.ts
new file mode 100644
index 00000000..fe1f37e1
--- /dev/null
+++ b/packages/vscode-ide-companion/src/types/approvalModeValueTypes.ts
@@ -0,0 +1,11 @@
+/**
+ * @license
+ * Copyright 2025 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Type for approval mode values
+ * Used in ACP protocol for controlling agent behavior
+ */
+export type ApprovalModeValue = 'plan' | 'default' | 'auto-edit' | 'yolo';
diff --git a/packages/vscode-ide-companion/src/types/chatTypes.ts b/packages/vscode-ide-companion/src/types/chatTypes.ts
index 90ebbb87..bafe154d 100644
--- a/packages/vscode-ide-companion/src/types/chatTypes.ts
+++ b/packages/vscode-ide-companion/src/types/chatTypes.ts
@@ -3,7 +3,8 @@
  * Copyright 2025 Qwen Team
  * SPDX-License-Identifier: Apache-2.0
  */
-import type { AcpPermissionRequest, ApprovalModeValue } from './acpTypes.js';
+import type { AcpPermissionRequest } from './acpTypes.js';
+import type { ApprovalModeValue } from './approvalModeValueTypes.js';
 
 export interface ChatMessage {
   role: 'user' | 'assistant';
diff --git a/packages/vscode-ide-companion/src/webview/App.tsx b/packages/vscode-ide-companion/src/webview/App.tsx
index 4bdf6622..1db91d39 100644
--- a/packages/vscode-ide-companion/src/webview/App.tsx
+++ b/packages/vscode-ide-companion/src/webview/App.tsx
@@ -43,7 +43,7 @@ import { InputForm } from './components/layout/InputForm.js';
 import { SessionSelector } from './components/layout/SessionSelector.js';
 import { FileIcon, UserIcon } from './components/icons/index.js';
 import { ApprovalMode, NEXT_APPROVAL_MODE } from '../types/acpTypes.js';
-import type { ApprovalModeValue } from '../types/acpTypes.js';
+import type { ApprovalModeValue } from '../types/approvalModeValueTypes.js';
 import type { PlanEntry } from '../types/chatTypes.js';
 
 export const App: React.FC = () => {
@@ -90,9 +90,13 @@ export const App: React.FC = () => {
   const getCompletionItems = React.useCallback(
     async (trigger: '@' | '/', query: string): Promise<CompletionItem[]> => {
       if (trigger === '@') {
-        if (!fileContext.hasRequestedFiles) {
-          fileContext.requestWorkspaceFiles();
-        }
+        console.log('[App] getCompletionItems @ called', {
+          query,
+          requested: fileContext.hasRequestedFiles,
+          workspaceFiles: fileContext.workspaceFiles.length,
+        });
+        // 始终根据当前 query 触发请求，让 hook 判断是否需要真正请求
+        fileContext.requestWorkspaceFiles(query);
 
         const fileIcon = <FileIcon />;
         const allItems: CompletionItem[] = fileContext.workspaceFiles.map(
@@ -109,7 +113,6 @@ export const App: React.FC = () => {
         );
 
         if (query && query.length >= 1) {
-          fileContext.requestWorkspaceFiles(query);
           const lowerQuery = query.toLowerCase();
           return allItems.filter(
             (item) =>
@@ -154,17 +157,39 @@ export const App: React.FC = () => {
 
   const completion = useCompletionTrigger(inputFieldRef, getCompletionItems);
 
+  // Track a lightweight signature of workspace files to detect content changes even when length is unchanged
+  const workspaceFilesSignature = useMemo(
+    () =>
+      fileContext.workspaceFiles
+        .map(
+          (file) =>
+            `${file.id}|${file.label}|${file.description ?? ''}|${file.path}`,
+        )
+        .join('||'),
+    [fileContext.workspaceFiles],
+  );
+
   // When workspace files update while menu open for @, refresh items so the first @ shows the list
   // Note: Avoid depending on the entire `completion` object here, since its identity
   // changes on every render which would retrigger this effect and can cause a refresh loop.
   useEffect(() => {
-    if (completion.isOpen && completion.triggerChar === '@') {
+    // Only auto-refresh when there's no query (first @ popup) to avoid repeated refreshes during search
+    if (
+      completion.isOpen &&
+      completion.triggerChar === '@' &&
+      !completion.query
+    ) {
       // Only refresh items; do not change other completion state to avoid re-renders loops
       completion.refreshCompletion();
     }
     // Only re-run when the actual data source changes, not on every render
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [fileContext.workspaceFiles, completion.isOpen, completion.triggerChar]);
+  }, [
+    workspaceFilesSignature,
+    completion.isOpen,
+    completion.triggerChar,
+    completion.query,
+  ]);
 
   // Message submission
   const { handleSubmit: submitMessage } = useMessageSubmit({
diff --git a/packages/vscode-ide-companion/src/webview/WebViewProvider.ts b/packages/vscode-ide-companion/src/webview/WebViewProvider.ts
index b4da60ab..f2b36ab0 100644
--- a/packages/vscode-ide-companion/src/webview/WebViewProvider.ts
+++ b/packages/vscode-ide-companion/src/webview/WebViewProvider.ts
@@ -14,7 +14,7 @@ import { MessageHandler } from '../webview/MessageHandler.js';
 import { WebViewContent } from '../webview/WebViewContent.js';
 import { CliInstaller } from '../cli/cliInstaller.js';
 import { getFileName } from './utils/webviewUtils.js';
-import { type ApprovalModeValue } from '../types/acpTypes.js';
+import { type ApprovalModeValue } from '../types/approvalModeValueTypes.js';
 
 export class WebViewProvider {
   private panelManager: PanelManager;
diff --git a/packages/vscode-ide-companion/src/webview/components/layout/InputForm.tsx b/packages/vscode-ide-companion/src/webview/components/layout/InputForm.tsx
index fe86ea99..5c4a889a 100644
--- a/packages/vscode-ide-companion/src/webview/components/layout/InputForm.tsx
+++ b/packages/vscode-ide-companion/src/webview/components/layout/InputForm.tsx
@@ -20,7 +20,7 @@ import {
 import { CompletionMenu } from '../layout/CompletionMenu.js';
 import type { CompletionItem } from '../../../types/completionItemTypes.js';
 import { getApprovalModeInfoFromString } from '../../../types/acpTypes.js';
-import type { ApprovalModeValue } from '../../../types/acpTypes.js';
+import type { ApprovalModeValue } from '../../../types/approvalModeValueTypes.js';
 
 interface InputFormProps {
   inputText: string;
diff --git a/packages/vscode-ide-companion/src/webview/handlers/SessionMessageHandler.ts b/packages/vscode-ide-companion/src/webview/handlers/SessionMessageHandler.ts
index 0df3e0da..75ebe0b9 100644
--- a/packages/vscode-ide-companion/src/webview/handlers/SessionMessageHandler.ts
+++ b/packages/vscode-ide-companion/src/webview/handlers/SessionMessageHandler.ts
@@ -7,6 +7,7 @@
 import * as vscode from 'vscode';
 import { BaseMessageHandler } from './BaseMessageHandler.js';
 import type { ChatMessage } from '../../services/qwenAgentManager.js';
+import type { ApprovalModeValue } from '../../types/approvalModeValueTypes.js';
 
 /**
  * Session message handler
@@ -29,6 +30,8 @@ export class SessionMessageHandler extends BaseMessageHandler {
       'cancelStreaming',
       // UI action: open a new chat tab (new WebviewPanel)
       'openNewChatTab',
+      // Settings-related messages
+      'setApprovalMode',
     ].includes(messageType);
   }
 
@@ -112,6 +115,14 @@ export class SessionMessageHandler extends BaseMessageHandler {
         await this.handleCancelStreaming();
         break;
 
+      case 'setApprovalMode':
+        await this.handleSetApprovalMode(
+          message.data as {
+            modeId?: ApprovalModeValue;
+          },
+        );
+        break;
+
       default:
         console.warn(
           '[SessionMessageHandler] Unknown message type:',
@@ -1073,4 +1084,23 @@ export class SessionMessageHandler extends BaseMessageHandler {
       }
     }
   }
+
+  /**
+   * Set approval mode via agent (ACP session/set_mode)
+   */
+  private async handleSetApprovalMode(data?: {
+    modeId?: ApprovalModeValue;
+  }): Promise<void> {
+    try {
+      const modeId = data?.modeId || 'default';
+      await this.agentManager.setApprovalModeFromUi(modeId);
+      // No explicit response needed; WebView listens for modeChanged
+    } catch (error) {
+      console.error('[SessionMessageHandler] Failed to set mode:', error);
+      this.sendToWebView({
+        type: 'error',
+        data: { message: `Failed to set mode: ${error}` },
+      });
+    }
+  }
 }
diff --git a/packages/vscode-ide-companion/src/webview/hooks/file/useFileContext.ts b/packages/vscode-ide-companion/src/webview/hooks/file/useFileContext.ts
index eca8437d..8bccc658 100644
--- a/packages/vscode-ide-companion/src/webview/hooks/file/useFileContext.ts
+++ b/packages/vscode-ide-companion/src/webview/hooks/file/useFileContext.ts
@@ -34,6 +34,9 @@ export const useFileContext = (vscode: VSCodeAPI) => {
   // Whether workspace files have been requested
   const hasRequestedFilesRef = useRef(false);
 
+  // Last non-empty query to decide when to refetch full list
+  const lastQueryRef = useRef<string | undefined>(undefined);
+
   // Search debounce timer
   const searchTimerRef = useRef<NodeJS.Timeout | null>(null);
 
@@ -42,12 +45,10 @@ export const useFileContext = (vscode: VSCodeAPI) => {
    */
   const requestWorkspaceFiles = useCallback(
     (query?: string) => {
-      if (!hasRequestedFilesRef.current && !query) {
-        hasRequestedFilesRef.current = true;
-      }
+      const normalizedQuery = query?.trim();
 
       // If there's a query, clear previous timer and set up debounce
-      if (query && query.length >= 1) {
+      if (normalizedQuery && normalizedQuery.length >= 1) {
         if (searchTimerRef.current) {
           clearTimeout(searchTimerRef.current);
         }
@@ -55,14 +56,23 @@ export const useFileContext = (vscode: VSCodeAPI) => {
         searchTimerRef.current = setTimeout(() => {
           vscode.postMessage({
             type: 'getWorkspaceFiles',
-            data: { query },
+            data: { query: normalizedQuery },
           });
         }, 300);
+        lastQueryRef.current = normalizedQuery;
       } else {
-        vscode.postMessage({
-          type: 'getWorkspaceFiles',
-          data: query ? { query } : {},
-        });
+        // For empty query, request once initially and whenever we are returning from a search
+        const shouldRequestFullList =
+          !hasRequestedFilesRef.current || lastQueryRef.current !== undefined;
+
+        if (shouldRequestFullList) {
+          lastQueryRef.current = undefined;
+          hasRequestedFilesRef.current = true;
+          vscode.postMessage({
+            type: 'getWorkspaceFiles',
+            data: {},
+          });
+        }
       }
     },
     [vscode],
diff --git a/packages/vscode-ide-companion/src/webview/hooks/useWebViewMessages.ts b/packages/vscode-ide-companion/src/webview/hooks/useWebViewMessages.ts
index 7a3f7e06..1ee50b27 100644
--- a/packages/vscode-ide-companion/src/webview/hooks/useWebViewMessages.ts
+++ b/packages/vscode-ide-companion/src/webview/hooks/useWebViewMessages.ts
@@ -12,7 +12,7 @@ import type {
   ToolCall as PermissionToolCall,
 } from '../components/PermissionDrawer/PermissionRequest.js';
 import type { ToolCallUpdate } from '../../types/chatTypes.js';
-import type { ApprovalModeValue } from '../../types/acpTypes.js';
+import type { ApprovalModeValue } from '../../types/approvalModeValueTypes.js';
 import type { PlanEntry } from '../../types/chatTypes.js';
 
 interface UseWebViewMessagesProps {