Rebase of #1

Summary by CodeRabbit

• New Features

  • Unified ISO‑8601 date/time across API and UI; timestamps now use Instant/OffsetDateTime.
  • UI tables sort dates reliably via millisecond values.
  • OCPP JSON status respects request time zone (UTC in API; request-derived in UI).

• Refactor

  • Migrated entire codebase from Joda-Time to Java Time.
  • Reworked OCPP WebSocket pipeline and JSON mapper wiring for clearer dependency injection.
  • Centralized path settings in a new configuration structure.

• Tests

  • Switched to AssertJ and MockMvcTester; updated tests to Java Time.

• Chores

  • Removed Joda-Time and related adapters; refreshed test dependencies.