fix: handle platform locales and frozen block targeting

[twme-ai]

Summary

• prefer Paper's Player.locale() through a runtime compatibility layer while retaining Spigot's Player.getLocale() fallback
• consume the locale carried by PlayerLocaleChangeEvent and normalize language tags consistently
• resolve the frozen block in front of the server-reported click target before considering the block behind it
• explicitly resync the restored block state so an originally-native barrier remains visible after unfreezing
• extend the Mineflayer test to cover zh_TW, repeated right-click unfreezing, behind-block regressions, and native barrier restoration

A single Java 17 artifact remains compatible with Spigot, Paper, and Folia; the Paper-only locale method is isolated behind reflection, so separate platform builds are unnecessary.

Verification

• mvn -B test: 11 tests, 0 failures, 0 errors
• Spigot 1.19.4 Mineflayer E2E: passed
• Spigot 1.21.11 Mineflayer E2E: passed
• Paper 1.20.6 Mineflayer E2E: passed
• Folia 1.20.6 Mineflayer E2E: passed without region-thread violations
• Spigot, Paper, and Folia 26.2 startup/plugin-enable E2E: passed

The Mineflayer assertions verify the Traditional Chinese response, display entity lifecycle, absence of a second frozen block behind the target, and stone/barrier client-side restoration.