refactor(providers): move auth status checks into provider runtimes

Move provider authentication status logic out of the CLI auth route so auth checks
live with the provider implementations that understand each provider's install
and credential model.

Add provider-specific auth runtime classes for Claude, Codex, Cursor, and Gemini,
and expose them through the shared provider contract as `provider.auth`. Add a
provider auth service that resolves providers through the registry and delegates
status checks via `auth.getStatus()`.

Keep the existing `/api/cli/<provider>/status` endpoints, but make them thin route
adapters over the new provider auth service. This removes duplicated route-local
credential parsing and makes auth status a first-class provider capability beside
MCP and message handling.

server/modules/providers/list/cursor/cursor-auth.provider.ts

@@ -0,0 +1,143 @@
+import spawn from 'cross-spawn';
+
+import type { IProviderAuthRuntime } from '@/shared/interfaces.js';
+import type { ProviderAuthStatus } from '@/shared/types.js';
+
+type CursorLoginStatus = {
+  authenticated: boolean;
+  email: string | null;
+  method: string | null;
+  error?: string;
+};
+
+export class CursorAuthProvider implements IProviderAuthRuntime {
+  /**
+   * Checks whether the cursor-agent CLI is available on this host.
+   */
+  private checkInstalled(): boolean {
+    try {
+      spawn.sync('cursor-agent', ['--version'], { stdio: 'ignore', timeout: 5000 });
+      return true;
+    } catch {
+      return false;
+    }
+  }
+
+  /**
+   * Returns Cursor CLI installation and login status.
+   */
+  async getStatus(): Promise<ProviderAuthStatus> {
+    const installed = this.checkInstalled();
+
+    if (!installed) {
+      return {
+        installed,
+        provider: 'cursor',
+        authenticated: false,
+        email: null,
+        method: null,
+        error: 'Cursor CLI is not installed',
+      };
+    }
+
+    const login = await this.checkCursorLogin();
+
+    return {
+      installed,
+      provider: 'cursor',
+      authenticated: login.authenticated,
+      email: login.email,
+      method: login.method,
+      error: login.authenticated ? undefined : login.error || 'Not logged in',
+    };
+  }
+
+  /**
+   * Runs cursor-agent status and parses the login marker from stdout.
+   */
+  private checkCursorLogin(): Promise<CursorLoginStatus> {
+    return new Promise((resolve) => {
+      let processCompleted = false;
+      let childProcess: ReturnType<typeof spawn> | undefined;
+
+      const timeout = setTimeout(() => {
+        if (!processCompleted) {
+          processCompleted = true;
+          childProcess?.kill();
+          resolve({
+            authenticated: false,
+            email: null,
+            method: null,
+            error: 'Command timeout',
+          });
+        }
+      }, 5000);
+
+      try {
+        childProcess = spawn('cursor-agent', ['status']);
+      } catch {
+        clearTimeout(timeout);
+        processCompleted = true;
+        resolve({
+          authenticated: false,
+          email: null,
+          method: null,
+          error: 'Cursor CLI not found or not installed',
+        });
+        return;
+      }
+
+      let stdout = '';
+      let stderr = '';
+
+      childProcess.stdout?.on('data', (data: Buffer) => {
+        stdout += data.toString();
+      });
+
+      childProcess.stderr?.on('data', (data: Buffer) => {
+        stderr += data.toString();
+      });
+
+      childProcess.on('close', (code) => {
+        if (processCompleted) {
+          return;
+        }
+        processCompleted = true;
+        clearTimeout(timeout);
+
+        if (code === 0) {
+          const emailMatch = stdout.match(/Logged in as ([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,})/i);
+          if (emailMatch?.[1]) {
+            resolve({ authenticated: true, email: emailMatch[1], method: 'cli' });
+            return;
+          }
+
+          if (stdout.includes('Logged in')) {
+            resolve({ authenticated: true, email: 'Logged in', method: 'cli' });
+            return;
+          }
+
+          resolve({ authenticated: false, email: null, method: null, error: 'Not logged in' });
+          return;
+        }
+
+        resolve({ authenticated: false, email: null, method: null, error: stderr || 'Not logged in' });
+      });
+
+      childProcess.on('error', () => {
+        if (processCompleted) {
+          return;
+        }
+        processCompleted = true;
+        clearTimeout(timeout);
+
+        resolve({
+          authenticated: false,
+          email: null,
+          method: null,
+          error: 'Cursor CLI not found or not installed',
+        });
+      });
+    });
+  }
+}

server/modules/providers/list/cursor/cursor.provider.ts

@@ -3,7 +3,9 @@ import os from 'node:os';
 import path from 'node:path';
 
 import { AbstractProvider } from '@/modules/providers/shared/base/abstract.provider.js';
+import { CursorAuthProvider } from '@/modules/providers/list/cursor/cursor-auth.provider.js';
 import { CursorMcpProvider } from '@/modules/providers/list/cursor/cursor-mcp.provider.js';
+import type { IProviderAuthRuntime } from '@/shared/interfaces.js';
 import type { FetchHistoryOptions, FetchHistoryResult, NormalizedMessage } from '@/shared/types.js';
 import { createNormalizedMessage, generateMessageId, readObjectRecord } from '@/shared/utils.js';
 
@@ -34,6 +36,7 @@ function readRawProviderMessage(raw: unknown): RawProviderMessage | null {
 
 export class CursorProvider extends AbstractProvider {
   readonly mcp = new CursorMcpProvider();
+  readonly auth: IProviderAuthRuntime = new CursorAuthProvider();
 
   constructor() {
     super('cursor');