Add Russian (ru) locale with MiniMessage formatting

[Copilot]

Community-contributed Russian translation switching from legacy & color codes to the MiniMessage formatting system, with grammatical corrections throughout.

Changes

• New file: src/main/resources/locales/ru.yml — full Russian translation covering all keys (admin commands, player commands, GUI elements, conversations)
• Format: MiniMessage tags (<green>, <red>, <aqua>, <bold>, etc.) replacing legacy codes
• Bug fixes on submitted translation:
  • level.gui.buttons.material.name: <white> → </white> (missing closing slash)
  • level.conversations.value-underwater: added missing </gray> closing tag

Example of the new formatting style:

# Before (legacy, as seen in uk.yml)
island-level-is: "&a Island level is &b[level]"

# After (MiniMessage, ru.yml)
island-level-is: '<green>Уровень острова: <aqua>[level]</aqua></green>'

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• hub.spigotmc.org
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.14/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.14/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.14 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.14/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/Level/Level org.codehaus.plexus.classworlds.launcher.Launcher test -q (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)