Brand the fork as Hellion Chat with independent plugin state

Switch the assembly name to HellionChat so Dalamud uses
pluginConfigs/HellionChat for our config file and database
directory, instead of sharing those locations with the upstream
Chat 2 plugin. Code namespace stays ChatTwo.* so upstream
cherry-picks apply cleanly.

Rename the DalamudPackager manifest to HellionChat.yaml with
fork-specific name, author, repo URL, description, tags and
changelog. Plugin.PluginName becomes "Hellion Chat".

Add a one-shot migration in the plugin constructor that runs
before GetPluginConfig: if pluginConfigs/ChatTwo.json or the
ChatTwo/ directory exist and our equivalents don't, move them
into the HellionChat layout. Idempotent: only fires on the first
load where legacy paths are present and ours are not.

ChatTwo/Plugin.cs

@@ -19,7 +19,7 @@ namespace ChatTwo;
 // ReSharper disable once ClassNeverInstantiated.Global
 public sealed class Plugin : IDalamudPlugin
 {
-    public const string PluginName = "Chat 2";
+    public const string PluginName = "Hellion Chat";
 
     [PluginService] public static IPluginLog Log { get; private set; } = null!;
     [PluginService] public static IDalamudPluginInterface Interface { get; private set; } = null!;
@@ -86,6 +86,11 @@ public sealed class Plugin : IDalamudPlugin
         {
             GameStarted = Process.GetCurrentProcess().StartTime.ToUniversalTime();
 
+            // Hellion Chat: take over config + database from upstream ChatTwo
+            // before Dalamud loads our plugin config. Idempotent: only acts on
+            // the first start where the legacy paths exist and ours don't.
+            MigrateFromChatTwoLayout();
+
             Config = Interface.GetPluginConfig() as Configuration ?? new Configuration();
 
 #pragma warning disable CS0618 // Type or member is obsolete
@@ -241,6 +246,37 @@ public sealed class Plugin : IDalamudPlugin
         ServerCore?.DisposeAsync().AsTask().Wait();
     }
 
+    private static void MigrateFromChatTwoLayout()
+    {
+        try
+        {
+            var pluginConfigsDir = Interface.ConfigDirectory.Parent?.FullName;
+            if (pluginConfigsDir is null)
+                return;
+
+            var legacyConfigFile = Path.Combine(pluginConfigsDir, "ChatTwo.json");
+            var legacyConfigDir = Path.Combine(pluginConfigsDir, "ChatTwo");
+            var ourConfigFile = Path.Combine(pluginConfigsDir, "HellionChat.json");
+            var ourConfigDir = Interface.ConfigDirectory.FullName;
+
+            if (!File.Exists(ourConfigFile) && File.Exists(legacyConfigFile))
+            {
+                File.Move(legacyConfigFile, ourConfigFile);
+                Log.Information($"HellionChat: migrated config file {legacyConfigFile} → {ourConfigFile}");
+            }
+
+            if (!Directory.Exists(ourConfigDir) && Directory.Exists(legacyConfigDir))
+            {
+                Directory.Move(legacyConfigDir, ourConfigDir);
+                Log.Information($"HellionChat: migrated config dir {legacyConfigDir} → {ourConfigDir}");
+            }
+        }
+        catch (Exception e)
+        {
+            Log.Error(e, "HellionChat: layout migration failed, continuing with whatever exists");
+        }
+    }
+
     private void Draw()
     {
         ChatLogWindow.BeginFrame();