v2025.02.02

Cleanups and fixes:

• Check for active write API before enabling services, actions, selects, numbers and buttons. Fixes #86. Thanks @Prythi
• This new check now requires python_sonnenbatterie >= 0.6.0
• Removed unnecessary calls to coordinator.async_refresh() when initializing services, actions, selects, numbers and buttons which results in slightly faster startup time
• Add three new diagnostic sensors:
  • read_api: whether the v2 JSON-API read access is enabled
  • write_api: whether the v2 JSON-API write access is enabled
  • tou_max: displays the configured limit for threshold_p_max on ToU
• Enforce the configured tou_max limit on calls to set_tou_schedule()