fix(cli): pass api_url to UI for OAuth to ensure same backend is used

When user has a custom apiBaseUrl in config (e.g., staging v2.postgres.ai),
the CLI now passes this URL to the UI via api_url query param. This ensures
oauth_approve is called on the same backend where oauth_init created the session,
preventing 'OAuth session not found' errors due to API/UI backend mismatch.

Author: Nik Samokhvalov

cli/bin/postgres-ai.ts

@@ -2102,7 +2102,8 @@ auth
       }
 
       // Step 3: Open browser
-      const authUrl = `${uiBaseUrl}/cli/auth?state=${encodeURIComponent(params.state)}&code_challenge=${encodeURIComponent(params.codeChallenge)}&code_challenge_method=S256&redirect_uri=${encodeURIComponent(redirectUri)}`;
+      // Pass api_url so UI calls oauth_approve on the same backend where oauth_init created the session
+      const authUrl = `${uiBaseUrl}/cli/auth?state=${encodeURIComponent(params.state)}&code_challenge=${encodeURIComponent(params.codeChallenge)}&code_challenge_method=S256&redirect_uri=${encodeURIComponent(redirectUri)}&api_url=${encodeURIComponent(apiBaseUrl)}`;
 
       if (opts.debug) {
         console.log(`Debug: Auth URL: ${authUrl}`);