Upgrade to Spring Boot 4.0

[devondragon]

Summary

Upgrade the Demo App to Spring Boot 4.0 to test compatibility with the updated SpringUserFramework library.

Tasks

• Update Spring Boot version from 3.5.6 to 4.0.0
• Update ds-spring-user-framework dependency to 4.0.0-SNAPSHOT
• Update Java toolchain version if required
• Fix any breaking changes from Spring Boot 4
• Update Thymeleaf extras for Spring Security 7 compatibility
• Run tests and fix any failures
• Verify application runs correctly

Related

• This upgrade corresponds to the SpringUserFramework 4.0.0-SNAPSHOT release

[create-issue-branch]

Branch issue-46-Upgrade-to-Spring-Boot-4-0 created!