fix(heykel-savasi): allow /starths restart + accept unencrypted team-select

Two TvT (Heykel Savasi) event fixes found during mobile+PC client work:

- PeriodicTaskBasePlugIn: a forced start (GM /starths) no longer blocked while a
  previous run's TaskDuration window is still open. When an event finished early
  (team won / empty / before the 20-min duration) players are warped out but the
  periodic state stayed Started with a future NextRunUtc, so the guard returned on
  every tick and a re-start only worked after the full duration or a server
  restart. Force-finish the stale run when _isStartForced so the same execution
  falls through and prepares a fresh one; the NextRunUtc wait now applies to
  scheduled runs only.

- HeykelSavasiTeamSelectHandlerPlugIn: IsEncryptionExpected => false. The AdaMu
  client sends client-to-server packets unencrypted (like walk / animation /
  talk-to-npc), so the server was dropping the team-select (JOIN) packet.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/GameLogic/PlugIns/PeriodicTasks/PeriodicTaskBasePlugIn.cs

@@ -43,7 +43,21 @@ public abstract class PeriodicTaskBasePlugIn<TConfiguration, TState> : IPeriodic
 
         var state = this.GetStateByGameContext(gameContext);
 
-        if (state.NextRunUtc > DateTime.UtcNow)
+        // A forced start (GM command, e.g. /starths) must not be blocked while a previous run's
+        // TaskDuration window is still open. When an event finished early (e.g. a team won, a team was
+        // empty, or simply before the 20-minute TaskDuration elapsed) the players are warped out but the
+        // periodic state stays Started with a future NextRunUtc. Without this, the guard below returns on
+        // every tick and a re-start only worked after the full TaskDuration elapsed (or a server restart).
+        // Force-finish the stale run here so this same execution falls through and prepares a fresh one.
+        if (this._isStartForced && state.State == PeriodicTaskState.Started)
+        {
+            state.State = PeriodicTaskState.NotStarted;
+            state.NextRunUtc = DateTime.MinValue;
+            await this.OnFinishedAsync(state).ConfigureAwait(false);
+        }
+
+        // The NextRunUtc wait applies to scheduled runs only; a forced start bypasses it.
+        if (!this._isStartForced && state.NextRunUtc > DateTime.UtcNow)
         {
             return;
         }

src/GameServer/MessageHandler/MiniGames/HeykelSavasiTeamSelectHandlerPlugIn.cs

@@ -25,7 +25,9 @@ public class HeykelSavasiTeamSelectHandlerPlugIn : IPacketHandlerPlugIn
     private readonly HeykelSavasiJoinAction _joinAction = new();
 
     /// <inheritdoc/>
-    public bool IsEncryptionExpected => true;
+    // The AdaMu client sends client-to-server packets unencrypted (like every other working handler:
+    // walk, animation, talk-to-npc), so this must be false or the server drops the team-select packet.
+    public bool IsEncryptionExpected => false;
 
     /// <inheritdoc/>
     public byte Key => HeykelSavasiTeamSelect.Code;