auth: align API with current abilities

src/modules/auth.ts

@@ -57,6 +57,23 @@ export function createAuthModule(
       window.location.href = loginUrl;
     },
 
+    // Redirects the user to a provider's login page
+    loginWithProvider(provider: string, fromUrl: string = "/") {
+      // Build the full redirect URL
+      const redirectUrl = new URL(fromUrl, window.location.origin).toString();
+
+      // Build the provider login URL (google is the default, so no provider path needed)
+      const providerPath = provider === "google" ? "" : `/${provider}`;
+      const loginUrl = `${
+        options.serverUrl
+      }/api/apps/auth${providerPath}/login?app_id=${appId}&from_url=${encodeURIComponent(
+        redirectUrl
+      )}`;
+
+      // Redirect to the provider login page
+      window.location.href = loginUrl;
+    },
+
     // Logout the current user
     // Removes the token from localStorage and optionally redirects to a URL or reloads the page
     logout(redirectUrl?: string) {

src/modules/auth.types.ts

@@ -185,6 +185,28 @@ export interface AuthModule {
    */
   redirectToLogin(nextUrl: string): void;
 
+  /**
+   * Redirects the user to a third-party authentication provider's login page.
+   *
+   * Initiates OAuth/SSO login flow with providers like Google, Microsoft, etc. Requires a browser environment and can't be used in the backend.
+   *
+   * @param provider - Name of the supported authentication provider (e.g., 'google', 'microsoft').
+   * @param fromUrl - URL to redirect to after successful authentication. Defaults to '/'.
+   *
+   * @example
+   * ```typescript
+   * // Login with Google and return to current page
+   * base44.auth.loginWithProvider('google', window.location.pathname);
+   * ```
+   *
+   * @example
+   * ```typescript
+   * // Login with GitHub and redirect to dashboard
+   * base44.auth.loginWithProvider('microsoft', '/dashboard');
+   * ```
+   */
+  loginWithProvider(provider: string, fromUrl?: string): void;
+
   /**
    * Logs out the current user.
    *