feat: use native OS folder picker dialog in Electron mode

Electron 环境下改用系统原生文件夹选择对话框替代自定义 FolderPicker 组件，
浏览器环境保留原有 FolderPicker 作为 fallback（浏览器沙箱无法获取绝对路径）。

- electron/main.ts: 新增 `dialog:open-folder` IPC handler，调用
  `dialog.showOpenDialog` 并设置 openDirectory + createDirectory 属性，
  macOS 下支持在对话框内新建文件夹，对话框模态绑定 mainWindow
- electron/preload.ts: 在 electronAPI 中暴露 `dialog.openFolder()` 方法
- src/types/electron.d.ts: 新建全局类型声明，统一定义 window.electronAPI
  的完整类型，消除代码中散落的 `(window as any)` 类型断言
- src/hooks/useNativeFolderPicker.ts: 新建 hook 封装平台检测和原生对话框
  调用逻辑，返回 isElectron 标志和 openNativePicker 方法
- src/components/layout/ChatListPanel.tsx: 新增 openFolderPicker() 统一入口，
  Electron 走原生对话框、浏览器走 setFolderPickerOpen(true)；替换
  handleNewChat 中 4 处及文件夹按钮 onClick 共 5 处调用点；
  handleFolderSelect 改为 useCallback 并调整声明顺序避免引用前使用；
  清理 electronAPI 类型断言
- src/app/chat/[id]/page.tsx: 移除 `window as unknown as ...` 类型断言
- src/components/layout/ConnectionStatus.tsx: 移除 `(window as any)` 断言
- src/components/layout/InstallWizard.tsx: getInstallAPI() 简化为直接返回
  window.electronAPI?.install，移除 10 行手动类型定义

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/chat/[id]/page.tsx

@@ -182,9 +182,8 @@ export default function ChatSessionPage({ params }: ChatSessionPageProps) {
                     style={{ WebkitAppRegion: 'no-drag' } as React.CSSProperties}
                     onClick={() => {
                       if (sessionWorkingDir) {
-                        const w = window as unknown as { electronAPI?: { shell?: { openPath: (p: string) => void } } };
-                        if (w.electronAPI?.shell?.openPath) {
-                          w.electronAPI.shell.openPath(sessionWorkingDir);
+                        if (window.electronAPI?.shell?.openPath) {
+                          window.electronAPI.shell.openPath(sessionWorkingDir);
                         } else {
                           fetch('/api/files/open', {
                             method: 'POST',

src/components/layout/ChatListPanel.tsx

@@ -26,6 +26,7 @@ import {
 import { cn } from "@/lib/utils";
 import { usePanel } from "@/hooks/usePanel";
 import { useTranslation } from "@/hooks/useTranslation";
+import { useNativeFolderPicker } from "@/hooks/useNativeFolderPicker";
 import { ConnectionStatus } from "./ConnectionStatus";
 import { ImportSessionDialog } from "./ImportSessionDialog";
 import { FolderPicker } from "@/components/chat/FolderPicker";
@@ -119,6 +120,7 @@ export function ChatListPanel({ open, width }: ChatListPanelProps) {
   const router = useRouter();
   const { streamingSessionId, pendingApprovalSessionId, workingDirectory } = usePanel();
   const { t } = useTranslation();
+  const { isElectron, openNativePicker } = useNativeFolderPicker();
   const [sessions, setSessions] = useState<ChatSession[]>([]);
   const [hoveredSession, setHoveredSession] = useState<string | null>(null);
   const [deletingSession, setDeletingSession] = useState<string | null>(null);
@@ -131,13 +133,39 @@ export function ChatListPanel({ open, width }: ChatListPanelProps) {
   const [hoveredFolder, setHoveredFolder] = useState<string | null>(null);
   const [creatingChat, setCreatingChat] = useState(false);
 
+  const handleFolderSelect = useCallback(async (path: string) => {
+    try {
+      const res = await fetch("/api/chat/sessions", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ working_directory: path }),
+      });
+      if (res.ok) {
+        const data = await res.json();
+        window.dispatchEvent(new CustomEvent("session-created"));
+        router.push(`/chat/${data.session.id}`);
+      }
+    } catch {
+      // Silently fail
+    }
+  }, [router]);
+
+  const openFolderPicker = useCallback(async (defaultPath?: string) => {
+    if (isElectron) {
+      const path = await openNativePicker({ defaultPath, title: t('folderPicker.title') });
+      if (path) handleFolderSelect(path);
+    } else {
+      setFolderPickerOpen(true);
+    }
+  }, [isElectron, openNativePicker, t, handleFolderSelect]);
+
   const handleNewChat = useCallback(async () => {
     const lastDir = workingDirectory
       || (typeof window !== 'undefined' ? localStorage.getItem("codepilot:last-working-directory") : null);
 
     if (!lastDir) {
       // No saved directory — let user pick one
-      setFolderPickerOpen(true);
+      openFolderPicker();
       return;
     }
 
@@ -150,7 +178,7 @@ export function ChatListPanel({ open, width }: ChatListPanelProps) {
       if (!checkRes.ok) {
         // Directory is gone — clear stale value and prompt user
         localStorage.removeItem("codepilot:last-working-directory");
-        setFolderPickerOpen(true);
+        openFolderPicker();
         return;
       }
 
@@ -162,18 +190,18 @@ export function ChatListPanel({ open, width }: ChatListPanelProps) {
       if (!res.ok) {
         // Backend rejected it (e.g. INVALID_DIRECTORY) — prompt user
         localStorage.removeItem("codepilot:last-working-directory");
-        setFolderPickerOpen(true);
+        openFolderPicker();
         return;
       }
       const data = await res.json();
       router.push(`/chat/${data.session.id}`);
       window.dispatchEvent(new CustomEvent("session-created"));
     } catch {
-      setFolderPickerOpen(true);
+      openFolderPicker();
     } finally {
       setCreatingChat(false);
     }
-  }, [router, workingDirectory]);
+  }, [router, workingDirectory, openFolderPicker]);
 
   const toggleProject = useCallback((wd: string) => {
     setCollapsedProjects((prev) => {
@@ -263,23 +291,6 @@ export function ChatListPanel({ open, width }: ChatListPanelProps) {
     }
   };
 
-  const handleFolderSelect = async (path: string) => {
-    try {
-      const res = await fetch("/api/chat/sessions", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ working_directory: path }),
-      });
-      if (res.ok) {
-        const data = await res.json();
-        window.dispatchEvent(new CustomEvent("session-created"));
-        router.push(`/chat/${data.session.id}`);
-      }
-    } catch {
-      // Silently fail
-    }
-  };
-
   const isSearching = searchQuery.length > 0;
 
   const filteredSessions = searchQuery
@@ -341,7 +352,7 @@ export function ChatListPanel({ open, width }: ChatListPanelProps) {
               variant="outline"
               size="icon-sm"
               className="h-8 w-8 shrink-0"
-              onClick={() => setFolderPickerOpen(true)}
+              onClick={() => openFolderPicker()}
             >
               <HugeiconsIcon icon={FolderOpenIcon} className="h-3.5 w-3.5" />
               <span className="sr-only">{t('chatList.addProjectFolder')}</span>
@@ -408,9 +419,8 @@ export function ChatListPanel({ open, width }: ChatListPanelProps) {
                         onDoubleClick={(e) => {
                           e.stopPropagation();
                           if (group.workingDirectory) {
-                            const w = window as unknown as { electronAPI?: { shell?: { openPath: (p: string) => void } } };
-                            if (w.electronAPI?.shell?.openPath) {
-                              w.electronAPI.shell.openPath(group.workingDirectory);
+                            if (window.electronAPI?.shell?.openPath) {
+                              window.electronAPI.shell.openPath(group.workingDirectory);
                             } else {
                               fetch('/api/files/open', {
                                 method: 'POST',

src/components/layout/ConnectionStatus.tsx

@@ -31,8 +31,7 @@ export function ConnectionStatus() {
 
   const isElectron =
     typeof window !== "undefined" &&
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    !!(window as any).electronAPI?.install;
+    !!window.electronAPI?.install;
   const stableCountRef = useRef(0);
   const lastConnectedRef = useRef<boolean | null>(null);
   const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);

src/components/layout/InstallWizard.tsx

@@ -58,18 +58,7 @@ interface PrereqResult {
 
 function getInstallAPI() {
   if (typeof window !== "undefined") {
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    return (window as any).electronAPI?.install as
-      | {
-          checkPrerequisites: () => Promise<PrereqResult>;
-          start: (options?: { includeNode?: boolean }) => Promise<void>;
-          cancel: () => Promise<void>;
-          getLogs: () => Promise<string[]>;
-          onProgress: (
-            callback: (progress: InstallProgress) => void
-          ) => () => void;
-        }
-      | undefined;
+    return window.electronAPI?.install;
   }
   return undefined;
 }

src/hooks/useNativeFolderPicker.ts

@@ -0,0 +1,20 @@
+import { useCallback } from 'react';
+
+/**
+ * Hook that provides native folder picker functionality in Electron,
+ * with detection for browser fallback.
+ */
+export function useNativeFolderPicker() {
+  const isElectron = typeof window !== 'undefined' && !!window.electronAPI?.dialog?.openFolder;
+
+  const openNativePicker = useCallback(
+    async (options?: { defaultPath?: string; title?: string }): Promise<string | null> => {
+      if (!window.electronAPI?.dialog?.openFolder) return null;
+      const result = await window.electronAPI.dialog.openFolder(options);
+      return result.canceled ? null : result.filePaths[0] ?? null;
+    },
+    []
+  );
+
+  return { isElectron, openNativePicker };
+}

src/types/electron.d.ts

@@ -0,0 +1,44 @@
+/**
+ * Global type declarations for the Electron preload API.
+ * Exposed via contextBridge.exposeInMainWorld('electronAPI', ...) in electron/preload.ts.
+ */
+
+interface ElectronInstallAPI {
+  checkPrerequisites: () => Promise<{
+    hasNode: boolean;
+    nodeVersion?: string;
+    hasClaude: boolean;
+    claudeVersion?: string;
+  }>;
+  start: (options?: { includeNode?: boolean }) => Promise<void>;
+  cancel: () => Promise<void>;
+  getLogs: () => Promise<string[]>;
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  onProgress: (callback: (data: any) => void) => () => void;
+}
+
+interface ElectronAPI {
+  versions: {
+    electron: string;
+    node: string;
+    chrome: string;
+  };
+  shell: {
+    openPath: (path: string) => Promise<string>;
+  };
+  dialog: {
+    openFolder: (options?: {
+      defaultPath?: string;
+      title?: string;
+    }) => Promise<{ canceled: boolean; filePaths: string[] }>;
+  };
+  install: ElectronInstallAPI;
+}
+
+declare global {
+  interface Window {
+    electronAPI?: ElectronAPI;
+  }
+}
+
+export {};