Kotlin DSL loginPage usage

Missing Kotlin DSL property for loginPage in oneTimeTokenLogin

Title: Kotlin DSL: Missing loginPage property in oneTimeTokenLogin configurer

Description:

Current Behavior

When configuring One-Time Token (OTT) login using the Spring Security Kotlin DSL, the loginPage property is not directly available as a property assignment (e.g., loginPage = "/login"). Instead, developers must use the it lambda parameter to call the Java-style setter method on the underlying OneTimeTokenLoginConfigurer:

// Current workaround
http.oneTimeTokenLogin {
    it.loginPage("/login")
    it.tokenGenerationSuccessHandler(myHandler)
}

Start at the Kotlin DSL oneTimeTokenLogin entry point and the underlying OneTimeTokenLoginConfigurer named in the issue. Compare the existing loginPage configuration with tokenGenerationSuccessHandler, then add coverage for loginPage = "/login". Done means the property assignment configures the same login page as it.loginPage("/login").