fix: address Codex review — Node auto-install, first-launch prompt, IPC consistency

P1: When Node.js is missing, auto-install via brew (macOS) or winget (Windows)
    instead of stopping and asking user to install manually.
P1: Auto-open install wizard on first disconnect detection in Electron,
    with localStorage flag to avoid re-prompting after dismissal.
P2: IPC install:start now throws on concurrent calls instead of returning
    silent { error } object. Removed unused return values from handlers.

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

Author: 7418

electron/main.ts

@@ -418,20 +418,28 @@ app.whenReady().then(async () => {
     return { hasNode, nodeVersion, hasClaude, claudeVersion };
   });
 
-  ipcMain.handle('install:start', () => {
+  ipcMain.handle('install:start', (_event: Electron.IpcMainInvokeEvent, options?: { includeNode?: boolean }) => {
     if (installState.status === 'running') {
-      return { error: 'Installation is already running' };
+      throw new Error('Installation is already running');
     }
 
+    const needsNode = options?.includeNode === true;
+
     // Reset state
+    const steps: InstallStep[] = [];
+    if (needsNode) {
+      steps.push({ id: 'install-node', label: 'Installing Node.js', status: 'pending' });
+    }
+    steps.push(
+      { id: 'check-node', label: 'Checking Node.js', status: 'pending' },
+      { id: 'install-claude', label: 'Installing Claude Code', status: 'pending' },
+      { id: 'verify', label: 'Verifying installation', status: 'pending' },
+    );
+
     installState = {
       status: 'running',
       currentStep: null,
-      steps: [
-        { id: 'check-node', label: 'Checking Node.js', status: 'pending' },
-        { id: 'install-claude', label: 'Installing Claude Code', status: 'pending' },
-        { id: 'verify', label: 'Verifying installation', status: 'pending' },
-      ],
+      steps,
       logs: [],
     };
 
@@ -465,6 +473,83 @@ app.whenReady().then(async () => {
     // Run the installation sequence asynchronously
     (async () => {
       try {
+        // Step 0 (optional): Install Node.js via package manager
+        if (needsNode) {
+          setStep('install-node', 'running');
+
+          const nodeInstalled = await new Promise<boolean>((resolve) => {
+            const isWin = process.platform === 'win32';
+            const isMac = process.platform === 'darwin';
+            let cmd: string;
+            let args: string[];
+
+            if (isMac) {
+              // Try Homebrew
+              const brewPaths = ['/opt/homebrew/bin/brew', '/usr/local/bin/brew'];
+              const brewPath = brewPaths.find(p => fs.existsSync(p));
+              if (!brewPath) {
+                addLog('Homebrew not found. Cannot auto-install Node.js on macOS without Homebrew.');
+                resolve(false);
+                return;
+              }
+              cmd = brewPath;
+              args = ['install', 'node'];
+              addLog(`Running: ${brewPath} install node`);
+            } else if (isWin) {
+              cmd = 'winget';
+              args = ['install', '-e', '--id', 'OpenJS.NodeJS.LTS', '--accept-source-agreements', '--accept-package-agreements'];
+              addLog('Running: winget install -e --id OpenJS.NodeJS.LTS');
+            } else {
+              // Linux — no universal package manager
+              addLog('Auto-install of Node.js is not supported on this platform.');
+              resolve(false);
+              return;
+            }
+
+            const child = spawn(cmd, args, {
+              env: execEnv,
+              shell: isWin,
+              stdio: ['ignore', 'pipe', 'pipe'],
+            });
+
+            installProcess = child;
+
+            child.stdout?.on('data', (data: Buffer) => {
+              for (const line of data.toString().split('\n').filter(Boolean)) {
+                addLog(line);
+              }
+            });
+            child.stderr?.on('data', (data: Buffer) => {
+              for (const line of data.toString().split('\n').filter(Boolean)) {
+                addLog(line);
+              }
+            });
+            child.on('error', (err) => {
+              addLog(`Error: ${err.message}`);
+              resolve(false);
+            });
+            child.on('close', (code) => {
+              installProcess = null;
+              resolve(code === 0);
+            });
+          });
+
+          if (installState.status === 'cancelled') {
+            setStep('install-node', 'failed', 'Cancelled');
+            return;
+          }
+
+          if (!nodeInstalled) {
+            setStep('install-node', 'failed', 'Could not auto-install Node.js.');
+            installState.status = 'failed';
+            sendProgress();
+            return;
+          }
+
+          setStep('install-node', 'success');
+          addLog('Node.js installation completed.');
+        }
+
         // Step 1: Check node
         setStep('check-node', 'running');
         try {
@@ -576,13 +661,11 @@ app.whenReady().then(async () => {
         sendProgress();
       }
     })();
-
-    return { ok: true };
   });
 
   ipcMain.handle('install:cancel', () => {
     if (installState.status !== 'running') {
-      return { error: 'No installation is running' };
+      return;
     }
 
     installState.status = 'cancelled';
@@ -597,7 +680,6 @@ app.whenReady().then(async () => {
     }
 
     mainWindow?.webContents.send('install:progress', installState);
-    return { ok: true };
   });
 
   ipcMain.handle('install:get-logs', () => {

electron/preload.ts

@@ -9,7 +9,7 @@ contextBridge.exposeInMainWorld('electronAPI', {
   },
   install: {
     checkPrerequisites: () => ipcRenderer.invoke('install:check-prerequisites'),
-    start: () => ipcRenderer.invoke('install:start'),
+    start: (options?: { includeNode?: boolean }) => ipcRenderer.invoke('install:start', options),
     cancel: () => ipcRenderer.invoke('install:cancel'),
     getLogs: () => ipcRenderer.invoke('install:get-logs'),
     onProgress: (callback: (data: unknown) => void) => {

src/components/layout/ConnectionStatus.tsx

@@ -34,6 +34,7 @@ export function ConnectionStatus() {
   const stableCountRef = useRef(0);
   const lastConnectedRef = useRef<boolean | null>(null);
   const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const autoPromptedRef = useRef(false);
 
   // Use a ref-based approach to avoid circular deps between check and schedule
   const checkRef = useRef<() => void>(() => {});
@@ -87,6 +88,32 @@ export function ConnectionStatus() {
     checkStatus();
   }, [checkStatus]);
 
+  // Auto-prompt install wizard on first disconnect detection (Electron only)
+  useEffect(() => {
+    if (
+      status !== null &&
+      !status.connected &&
+      isElectron &&
+      !autoPromptedRef.current &&
+      !dialogOpen &&
+      !wizardOpen
+    ) {
+      const dismissed = localStorage.getItem("codepilot:install-wizard-dismissed");
+      if (!dismissed) {
+        autoPromptedRef.current = true;
+        setWizardOpen(true); // eslint-disable-line react-hooks/set-state-in-effect -- intentional: auto-prompt on first disconnect
+      }
+    }
+  }, [status, isElectron, dialogOpen, wizardOpen]);
+
+  const handleWizardOpenChange = useCallback((open: boolean) => {
+    setWizardOpen(open);
+    if (!open) {
+      // Remember that user dismissed the wizard so we don't auto-prompt again
+      localStorage.setItem("codepilot:install-wizard-dismissed", "1");
+    }
+  }, []);
+
   const connected = status?.connected ?? false;
 
   return (
@@ -199,7 +226,7 @@ export function ConnectionStatus() {
 
       <InstallWizard
         open={wizardOpen}
-        onOpenChange={setWizardOpen}
+        onOpenChange={handleWizardOpenChange}
         onInstallComplete={handleManualRefresh}
       />
     </>

src/components/layout/InstallWizard.tsx

@@ -40,7 +40,6 @@ interface InstallWizardProps {
 
 type WizardPhase =
   | "checking"
-  | "node-missing"
   | "already-installed"
   | "installing"
   | "success"
@@ -57,7 +56,7 @@ function getInstallAPI() {
             hasClaude: boolean;
             claudeVersion?: string;
           }>;
-          start: () => Promise<void>;
+          start: (options?: { includeNode?: boolean }) => Promise<void>;
           cancel: () => Promise<void>;
           getLogs: () => Promise<string[]>;
           onProgress: (
@@ -104,7 +103,7 @@ export function InstallWizard({
     scrollToBottom();
   }, [logs, scrollToBottom]);
 
-  const startInstall = useCallback(async () => {
+  const startInstall = useCallback(async (options?: { includeNode?: boolean }) => {
     const api = getInstallAPI();
     if (!api) return;
 
@@ -124,7 +123,7 @@ export function InstallWizard({
     });
 
     try {
-      await api.start();
+      await api.start(options);
     } catch (err: unknown) {
       setPhase("failed");
       const msg = err instanceof Error ? err.message : String(err);
@@ -143,31 +142,30 @@ export function InstallWizard({
     try {
       const result = await api.checkPrerequisites();
 
-      if (!result.hasNode) {
-        setPhase("node-missing");
+      if (result.hasClaude) {
         setLogs((prev) => [
           ...prev,
-          "Node.js not found.",
+          `Node.js ${result.nodeVersion} found.`,
+          `Claude Code ${result.claudeVersion} already installed.`,
         ]);
+        setPhase("already-installed");
         return;
       }
 
-      setLogs((prev) => [
-        ...prev,
-        `Node.js ${result.nodeVersion} found.`,
-      ]);
-
-      if (result.hasClaude) {
-        setPhase("already-installed");
+      if (!result.hasNode) {
         setLogs((prev) => [
           ...prev,
-          `Claude Code ${result.claudeVersion} already installed.`,
+          "Node.js not found. Will attempt to install Node.js and Claude Code...",
         ]);
-        return;
+        startInstall({ includeNode: true });
+      } else {
+        setLogs((prev) => [
+          ...prev,
+          `Node.js ${result.nodeVersion} found.`,
+          "Claude Code not found. Starting installation...",
+        ]);
+        startInstall();
       }
-
-      setLogs((prev) => [...prev, "Claude Code not found. Starting installation..."]);
-      startInstall();
     } catch (err: unknown) {
       setPhase("failed");
       const msg = err instanceof Error ? err.message : String(err);
@@ -268,26 +266,6 @@ export function InstallWizard({
             </div>
           )}
 
-          {phase === "node-missing" && (
-            <div className="rounded-lg bg-red-500/10 px-4 py-3 text-sm space-y-2">
-              <p className="font-medium text-red-700 dark:text-red-400">
-                Node.js 18+ is required
-              </p>
-              <p className="text-muted-foreground">
-                Please install it from{" "}
-                <a
-                  href="https://nodejs.org"
-                  target="_blank"
-                  rel="noopener noreferrer"
-                  className="underline text-blue-600 dark:text-blue-400"
-                >
-                  https://nodejs.org
-                </a>{" "}
-                and try again.
-              </p>
-            </div>
-          )}
-
           {phase === "already-installed" && (
             <div className="flex items-center gap-3 rounded-lg bg-emerald-500/10 px-4 py-3">
               <CheckIcon className="size-5 text-emerald-500 shrink-0" />
@@ -342,12 +320,6 @@ export function InstallWizard({
             {copied ? "Copied" : "Copy Logs"}
           </Button>
 
-          {phase === "node-missing" && (
-            <Button size="sm" onClick={checkPrereqs}>
-              Retry
-            </Button>
-          )}
-
           {phase === "installing" && (
             <Button variant="destructive" size="sm" onClick={handleCancel}>
               Cancel