feat(CS): persist owner/phase/registrations across restarts via plugin config JSON

Castle Siege state was in-memory, so the castle owner (and thus the P4 hunting-map
reward) reset on every server restart/redeploy. Now the context marks itself dirty
on any persistable change (phase transition, registration, owner set); the plugin's
periodic tick writes a snapshot into its own PlugInConfiguration CustomConfiguration
(a JSON blob already stored in PostgreSQL - no schema migration) and restores it on
startup. Battle state (defenses/switches/occupier) stays transient. +2 unit tests.

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

src/GameLogic/PlugIns/PeriodicTasks/CastleSiegeEventPlugIn.cs

@@ -69,7 +69,12 @@ public sealed class CastleSiegeEventPlugIn : IPeriodicTaskPlugIn, ISupportCustom
     {
         var context = Contexts.GetOrAdd(gameContext, gc =>
         {
-            var created = new CastleSiegeContext(this.Configuration ?? new CastleSiegeConfiguration());
+            var config = this.Configuration ?? new CastleSiegeConfiguration();
+            var created = new CastleSiegeContext(config);
+
+            // Restore state persisted before the last restart (owner/phase/registrations) BEFORE subscribing,
+            // so restoring doesn't announce phases or re-spawn defenses.
+            created.RestoreState(config.PersistedOwnerGuildName, config.PersistedPhase, config.PersistedPhaseStartedUtc, config.PersistedRegisteredGuilds);
 
             // Announce phase changes to the whole server and, when the siege begins, warp registered members.
             created.PhaseChanged += phase => _ = OnPhaseChangedAsync(gc, created, phase);
@@ -84,6 +89,12 @@ public sealed class CastleSiegeEventPlugIn : IPeriodicTaskPlugIn, ISupportCustom
         {
             await ProcessSiegeTickAsync(gameContext, context).ConfigureAwait(false);
         }
+
+        // Persist owner/phase/registrations to the database whenever they changed, so they survive a restart.
+        if (context.ConsumeDirty())
+        {
+            await this.PersistStateAsync(gameContext, context).ConfigureAwait(false);
+        }
     }
 
     /// <inheritdoc />
@@ -124,6 +135,41 @@ public sealed class CastleSiegeEventPlugIn : IPeriodicTaskPlugIn, ISupportCustom
         }
     }
 
+    private async ValueTask PersistStateAsync(GameContext gameContext, CastleSiegeContext context)
+    {
+        try
+        {
+            if (this.Configuration is not { } config)
+            {
+                return;
+            }
+
+            // Snapshot the live context into the persisted config fields.
+            config.PersistedOwnerGuildName = context.OwnerGuildName;
+            config.PersistedPhase = context.Phase;
+            config.PersistedPhaseStartedUtc = context.PhaseStartedUtc;
+            config.PersistedRegisteredGuilds = context.RegisteredGuilds.ToList();
+
+            // Write the plugin's custom-configuration JSON row back to the database (durable across restarts).
+            var pluginTypeId = typeof(CastleSiegeEventPlugIn).GUID;
+            using var ctx = gameContext.PersistenceContextProvider.CreateNewContext(gameContext.Configuration);
+            var configurations = await ctx.GetAsync<PlugInConfiguration>().ConfigureAwait(false);
+            var row = configurations.FirstOrDefault(c => c.TypeId == pluginTypeId);
+            if (row is null)
+            {
+                return;
+            }
+
+            row.SetConfiguration(config, gameContext.PlugInManager.CustomConfigReferenceHandler);
+            await ctx.SaveChangesAsync().ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            gameContext.LoggerFactory.CreateLogger<CastleSiegeEventPlugIn>()
+                .LogError(ex, "Castle Siege: error while persisting state to the database.");
+        }
+    }
+
     private static ValueTask AnnounceAsync(IGameContext gameContext, string message)
         => gameContext.ForEachPlayerAsync(player =>
             player.InvokeViewPlugInAsync<IShowMessagePlugIn>(p => p.ShowMessageAsync(message, MessageType.GoldenCenter)).AsTask());