Refactor CLI authentication module location (#660)

* refactor: move cli-auth.js to the providers folder

* fix: expired oauth token returns no error message

server/providers/gemini/status.js

@@ -0,0 +1,111 @@
+/**
+ * Gemini Provider Status
+ *
+ * Checks whether Gemini CLI is installed and whether the user
+ * has valid authentication credentials.
+ *
+ * @module providers/gemini/status
+ */
+
+import { execFileSync } from 'child_process';
+import { promises as fs } from 'fs';
+import path from 'path';
+import os from 'os';
+
+/**
+ * Check if Gemini CLI is installed.
+ * Uses GEMINI_PATH env var if set, otherwise looks for 'gemini' in PATH.
+ * @returns {boolean}
+ */
+export function checkInstalled() {
+  const cliPath = process.env.GEMINI_PATH || 'gemini';
+  try {
+    execFileSync(cliPath, ['--version'], { stdio: 'ignore', timeout: 5000 });
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Full status check: installation + authentication.
+ * @returns {Promise<import('../types.js').ProviderStatus>}
+ */
+export async function checkStatus() {
+  const installed = checkInstalled();
+
+  if (!installed) {
+    return {
+      installed,
+      authenticated: false,
+      email: null,
+      error: 'Gemini CLI is not installed'
+    };
+  }
+
+  const result = await checkCredentials();
+
+  return {
+    installed,
+    authenticated: result.authenticated,
+    email: result.email || null,
+    error: result.error || null
+  };
+}
+
+// ─── Internal helpers ───────────────────────────────────────────────────────
+
+async function checkCredentials() {
+  if (process.env.GEMINI_API_KEY && process.env.GEMINI_API_KEY.trim()) {
+    return { authenticated: true, email: 'API Key Auth' };
+  }
+
+  try {
+    const credsPath = path.join(os.homedir(), '.gemini', 'oauth_creds.json');
+    const content = await fs.readFile(credsPath, 'utf8');
+    const creds = JSON.parse(content);
+
+    if (creds.access_token) {
+      let email = 'OAuth Session';
+
+      try {
+        const tokenRes = await fetch(`https://oauth2.googleapis.com/tokeninfo?access_token=${creds.access_token}`);
+        if (tokenRes.ok) {
+          const tokenInfo = await tokenRes.json();
+          if (tokenInfo.email) {
+            email = tokenInfo.email;
+          }
+        } else if (!creds.refresh_token) {
+          return {
+            authenticated: false,
+            email: null,
+            error: 'Access token invalid and no refresh token found'
+          };
+        } else {
+          // Token might be expired but we have a refresh token, so CLI will refresh it
+          email = await getActiveAccountEmail() || email;
+        }
+      } catch {
+        // Network error, fallback to checking local accounts file
+        email = await getActiveAccountEmail() || email;
+      }
+
+      return { authenticated: true, email };
+    }
+
+    return { authenticated: false, email: null, error: 'No valid tokens found in oauth_creds' };
+  } catch {
+    return { authenticated: false, email: null, error: 'Gemini CLI not configured' };
+  }
+}
+
+async function getActiveAccountEmail() {
+  try {
+    const accPath = path.join(os.homedir(), '.gemini', 'google_accounts.json');
+    const accContent = await fs.readFile(accPath, 'utf8');
+    const accounts = JSON.parse(accContent);
+    return accounts.active || null;
+  } catch {
+    return null;
+  }
+}