fix(auth): improve CLI installation check reliability

Handle various error cases when checking if CLI is installed by examining exit code and output. This prevents false positives when the command is not actually available.

Author: moazbuilds

src/infra/engines/providers/claude/auth.ts

@@ -11,8 +11,13 @@ import { metadata } from './metadata.js';
  */
 async function isCliInstalled(command: string): Promise<boolean> {
   try {
-    await execa(command, ['--version'], { timeout: 3000, reject: false });
-    return true;
+    const result = await execa(command, ['--version'], { timeout: 3000, reject: false });
+    if (typeof result.exitCode === 'number' && result.exitCode === 0) return true;
+    const out = `${result.stdout ?? ''}\n${result.stderr ?? ''}`;
+    if (/not recognized as an internal or external command/i.test(out)) return false;
+    if (/command not found/i.test(out)) return false;
+    if (/No such file or directory/i.test(out)) return false;
+    return false;
   } catch {
     return false;
   }

src/infra/engines/providers/codex/auth.ts

@@ -21,8 +21,13 @@ async function resolveCodexHome(codexHome?: string): Promise<string> {
  */
 async function isCliInstalled(command: string): Promise<boolean> {
   try {
-    await execa(command, ['--version'], { timeout: 3000, reject: false });
-    return true;
+    const result = await execa(command, ['--version'], { timeout: 3000, reject: false });
+    if (typeof result.exitCode === 'number' && result.exitCode === 0) return true;
+    const out = `${result.stdout ?? ''}\n${result.stderr ?? ''}`;
+    if (/not recognized as an internal or external command/i.test(out)) return false;
+    if (/command not found/i.test(out)) return false;
+    if (/No such file or directory/i.test(out)) return false;
+    return false;
   } catch {
     return false;
   }

src/infra/engines/providers/cursor/auth.ts

@@ -11,8 +11,13 @@ import { metadata } from './metadata.js';
  */
 async function isCliInstalled(command: string): Promise<boolean> {
   try {
-    await execa(command, ['--version'], { timeout: 3000, reject: false });
-    return true;
+    const result = await execa(command, ['--version'], { timeout: 3000, reject: false });
+    if (typeof result.exitCode === 'number' && result.exitCode === 0) return true;
+    const out = `${result.stdout ?? ''}\n${result.stderr ?? ''}`;
+    if (/not recognized as an internal or external command/i.test(out)) return false;
+    if (/command not found/i.test(out)) return false;
+    if (/No such file or directory/i.test(out)) return false;
+    return false;
   } catch {
     return false;
   }