refactor: KISS/DRY/SOLID раунд + багфиксы радио/voice/message

Что сделано:
- RatingService (getDeterministicValue + cooldown — одна точка)
- ModerationHelper (trunc/err — одна точка)
- VoiceHelper (waitForCondition с таймаутом)
- SocialCommand (7 файлов → 1 Flavor enum)
- SwapCommand + CaseLookupCommand (Split SRP)
- PlayCommand 219→150, BotInitializer 182→135, RankCardGenerator (1→4)
- MetricsCollector 182→143, TrackScheduler 202→146, VoiceChannelManager 187→150
- QueueCommands 207→149, VoiceSetupPrefixCommand 183→146, ServerStatsService 187→150
- GuildMusicManager 167→150, SqlEconomyRepository 169→149, GenerateRatingsCommand 172→147
- RadioManager: таймауты, volume при старте, защита от утечки
- VoiceTracker: race condition fix + LevelUpNotifier
- MessageCooldownService: in-memory cache
- MessageListener: LevelUpNotifier вместо inline embed
- ResetLevelsButtonHandler: правильный парсинг кнопки
- OkHttp: java.net.http → OkHttp 5.4.0
- SlowmodeCommandTest: SelfMember fix
Всё: 415 tests, 2 pre-existing, checkstyle чисто

gradle/libs.versions.toml

@@ -10,6 +10,7 @@ caffeine = "3.2.0"
 guice = "7.0.0"
 sqlite = "3.49.1.0"
 hikaricp = "6.3.0"
+okhttp = "5.4.0"
 junit = "5.12.1"
 mockito = "5.15.2"
 junitPlatformLauncher = "1.12.1"
@@ -29,6 +30,8 @@ caffeine = { module = "com.github.ben-manes.caffeine:caffeine", version.ref = "c
 guice = { module = "com.google.inject:guice", version.ref = "guice" }
 sqlite-jdbc = { module = "org.xerial:sqlite-jdbc", version.ref = "sqlite" }
 hikaricp = { module = "com.zaxxer:HikariCP", version.ref = "hikaricp" }
+okhttp = { module = "com.squareup.okhttp3:okhttp", version.ref = "okhttp" }
+logging-interceptor = { module = "com.squareup.okhttp3:logging-interceptor", version.ref = "okhttp" }
 junit-jupiter = { module = "org.junit.jupiter:junit-jupiter", version.ref = "junit" }
 mockito-core = { module = "org.mockito:mockito-core", version.ref = "mockito" }
 mockito-junit-jupiter = { module = "org.mockito:mockito-junit-jupiter", version.ref = "mockito" }