Add built-in mute system with /lmute and /lunmute commands

- Added MuteManager for handling mutes with persistence (mutes.json)
- Added /lmute <nick> <time> [-s] [reason] command
- Added /lunmute <nick> [-s] command
- Time formats: 1d, 2h, 30m, 60s, 0 for permanent
- -s flag for silent mute/unmute (no broadcast)
- Mute check integrated into ChatListener
- Removed LibertyBans API dependency (using built-in system)

src/main/resources/plugin.yml

@@ -97,6 +97,18 @@ commands:
     permission: gradient.admin
     aliases: [gradientadmin, азкуашч, пкфвшуетефвьшт]
 
+  lmute:
+    description: Mute a player
+    usage: /lmute <player> <time> [-s] [reason]
+    permission: lochat.mute
+    aliases: [дьгеу]
+
+  lunmute:
+    description: Unmute a player
+    usage: /lunmute <player> [-s]
+    permission: lochat.unmute
+    aliases: [дгтьгеу]
+
 permissions:
   chat.global.use:
     default: true
@@ -140,3 +152,7 @@ permissions:
     default: op
   lochat.admin:
     default: op
+  lochat.mute:
+    default: op
+  lochat.unmute:
+    default: op