Verify and document GraalVM native image support

[pgatzka]

User Story

As a developer, I want to use Graphite in a GraalVM native image so that I can achieve faster startup times.

Description

Test and document GraalVM native image compilation:

Tasks:

• Verify native image compilation succeeds
• Add reflection configuration if needed
• Add native-image test in CI
• Document native image usage

Test scope:

• Basic client operations work
• All serialization/deserialization works
• Spring Boot native support verified

Acceptance Criteria

• Native image compiles successfully
• Native image passes functional tests
• Reflection configuration added if needed
• Native hints registered for Spring AOT
• Documentation includes native image guide
• CI includes native image build test
• Implemented code is covered with automated tests
• Documentation has been updated