Update organization authentication methods

Update the authentication methods configuration for an organization. This allows admins to configure single or multi-factor authentication.

Validation Rules:

• Minimum 1 step, maximum 3 steps
• Each step must have a unique order (1, 2, or 3)
• No duplicate methods within the same step
• No method can appear in multiple steps
• Each step must have at least one allowed method

Available Methods:

• password: Email/password authentication
• otp: One-time password via email
• google: Google OAuth 2.0
• microsoft: Microsoft OAuth 2.0
• azureAd: Azure Active Directory
• samlSso: SAML 2.0 Single Sign-On
• oauth: Generic OAuth 2.0 provider

Example - Single Factor (Password or Google):

{
  "authMethod": [
    { "order": 1, "allowedMethods": [{ "type": "password" }, { "type": "google" }] }
  ]
}

Example - Two Factor (Password + OTP):

{
  "authMethod": [
    { "order": 1, "allowedMethods": [{ "type": "password" }] },
    { "order": 2, "allowedMethods": [{ "type": "otp" }] }
  ]
}

Admin Access Required: Only organization admins can update auth configuration.