feat: chat channel system (/join /leave /channel)

- config-driven channels in config/channels.yml (global, local, staff, trade) with
  emoji, colors, prefix, radius, cooldowns, permissions and aliases
- Channel record + ChannelConfig loader wired into ConfigManager (reload supported)
- ChannelService (api) + ConcurrentHashMap-backed ChannelServiceImpl, joined in
  ServiceRegistry; default channel join treated as 'not in channel'
- JoinChannelCommand / LeaveChannelCommand / ChannelCommand (+ tab completion),
  registered in CommandManager; plugin.yml commands + permissions
- ChatEventListener routes AsyncChatEvent to the active channel: per-channel
  cooldown, local-radius viewer filtering, channel-aware renderer
- EnhancedChatRenderer supports Channel overload (emojiFor/prefixText/channelColor)
- ChannelServiceImplTest covering join/leave/permissions/aliases

src/main/java/com/loki/lochat/commands/CommandManager.java

@@ -8,7 +8,10 @@ import com.loki.lochat.commands.admin.chat.ClearChatCommand;
 import com.loki.lochat.commands.admin.chat.ClearChatConfigCommand;
 import com.loki.lochat.commands.admin.system.LoChatCommand;
 import com.loki.lochat.commands.admin.system.ReloadConfigCommand;
+import com.loki.lochat.commands.chat.ChannelCommand;
 import com.loki.lochat.commands.chat.GlobalChatCommand;
+import com.loki.lochat.commands.chat.JoinChannelCommand;
+import com.loki.lochat.commands.chat.LeaveChannelCommand;
 import com.loki.lochat.commands.chat.LocalChatCommand;
 import com.loki.lochat.commands.messaging.IgnoreCommand;
 import com.loki.lochat.commands.messaging.IgnoreListCommand;
@@ -54,6 +57,11 @@ public class CommandManager {
         reg("g",          new GlobalChatCommand(plugin));
         reg("l",          new LocalChatCommand(plugin));
 
+        // ── Каналы ─────────────────────────────────────────────────────────────
+        regTab("join",     new JoinChannelCommand(plugin));
+        reg("leave",       new LeaveChannelCommand(plugin));
+        regTab("channel",  new ChannelCommand(plugin));
+
         // ── Личные сообщения / игнор ──────────────────────────────────────────
         reg("msg",        new MsgCommand(plugin));
         reg("reply",      new ReplyCommand(plugin));