chore: housekeeping — linter & formatter setup

Add .prettierrc.json, .markdownlint.json, .yamllint.yaml, .gitattributes
Run CSharpier, Prettier and markdownlint across the entire codebase.
No logic changes — formatting, using order and line endings only.

HellionChat/IpcManager.cs

@@ -9,7 +9,15 @@ internal sealed class IpcManager : IDisposable
     private ICallGateProvider<string> RegisterGate { get; }
     private ICallGateProvider<string, object?> UnregisterGate { get; }
     private ICallGateProvider<object?> AvailableGate { get; }
-    private ICallGateProvider<string, PlayerPayload?, ulong, Payload?, SeString?, SeString?, object?> InvokeGate { get; }
+    private ICallGateProvider<
+        string,
+        PlayerPayload?,
+        ulong,
+        Payload?,
+        SeString?,
+        SeString?,
+        object?
+    > InvokeGate { get; }
 
     internal List<string> Registered { get; } = [];
 
@@ -23,12 +31,27 @@ internal sealed class IpcManager : IDisposable
         UnregisterGate = Plugin.Interface.GetIpcProvider<string, object?>("HellionChat.Unregister");
         UnregisterGate.RegisterAction(Unregister);
 
-        InvokeGate = Plugin.Interface.GetIpcProvider<string, PlayerPayload?, ulong, Payload?, SeString?, SeString?, object?>("HellionChat.Invoke");
+        InvokeGate = Plugin.Interface.GetIpcProvider<
+            string,
+            PlayerPayload?,
+            ulong,
+            Payload?,
+            SeString?,
+            SeString?,
+            object?
+        >("HellionChat.Invoke");
 
         AvailableGate.SendMessage();
     }
 
-    internal void Invoke(string id, PlayerPayload? sender, ulong contentId, Payload? payload, SeString? senderString, SeString? content)
+    internal void Invoke(
+        string id,
+        PlayerPayload? sender,
+        ulong contentId,
+        Payload? payload,
+        SeString? senderString,
+        SeString? content
+    )
     {
         InvokeGate.SendMessage(id, sender, contentId, payload, senderString, content);
     }