Marstek 0.2.2-rc1

Pre-release for Marstek binding UDP client hardening and config improvements.

Included changes:

• Reused UDP socket client with request/response correlation
• Retry logic and improved null/concurrency safety
• Refresh interval behavior softened (warn below 5s, no hard clamp)
• Exposed remote UDP port and local bind port in Thing configuration UI
• XML config schema fixes and formatting updates

Built and validated in module build.