add changelog and bump patch version to 2.0.5

Assisted-by: Claude Opus 4.8

Author: endel

CHANGELOG.md

@@ -0,0 +1,21 @@
+# Changelog
+
+All notable changes to this project are documented in this file.
+
+This changelog starts at 2.0.5 — see the [GitHub Releases](https://github.com/endel/NativeWebSocket/releases) page for earlier versions.
+
+## 2.0.5 - 2026-08-06
+
+### Fixed
+
+- **Close codes outside the enum are no longer reported as `1004`.** `WebSocketHelpers.ParseCloseCodeEnum()` collapsed every code without a matching `WebSocketCloseCode` member into `WebSocketCloseCode.Undefined` (1004), so application close codes (RFC 6455 reserves 3000-4999 for applications) were indistinguishable from one another. Any valid close code (1000-4999) is now preserved as-is.
+
+- **The closing handshake now echoes the code the server sent.** When a close frame arrived, the receive loop called `Close()` — which short-circuits on its `State == Open` check, because a socket that just received a close frame is in `CloseReceived`. The result was that no closing handshake response was ever sent, and had it been, it would have carried `Normal` (1000) rather than the received code. Servers read their own close code from that response, so a deliberate close looked to them like a dropped connection (1006). The response is now sent via `CloseOutputAsync` with the received code.
+
+  Together these fixes resolve [colyseus/colyseus#948](https://github.com/colyseus/colyseus/issues/948), where a server-side `client.leave(4000)` (Colyseus' `CloseCode.CONSENTED`) surfaced on the client as close code 1004, and made the server run `onDrop()` — opening a reconnection window — instead of treating the leave as consented. Thanks to [@trueicecold](https://github.com/trueicecold) for the detailed report.
+
+### Changed
+
+- **Renamed the Unity WebGL plugin files** from `WebSocket.jslib` / `WebSocket.jspre` to `NativeWebSocket.jslib` / `NativeWebSocket.jspre`. Unity flattens WebGL plugins into a single output directory, so the previous generic name collided with identically named plugins from other packages (Photon ships a `WebSocket.jslib`), failing the build with `Plugin 'WebSocket.jslib' is used from several locations`. Only the file names changed — the exported JavaScript symbols are unchanged, and nothing references these files by name. Thanks to [@Alaadel](https://github.com/Alaadel) for reporting.
+
+  **Upgrading:** `.unitypackage` imports do not delete removed files. If you upgrade in place, delete the old `WebSocket.jslib` and `WebSocket.jspre` from your project, otherwise the new and old plugins will collide with each other. Users installing via UPM are not affected.

integrations/Unity/package.json

@@ -1,6 +1,6 @@
 {
   "name": "com.endel.nativewebsocket",
-  "version": "2.0.4",
+  "version": "2.0.5",
   "description": "WebSocket client for Unity - with no external dependencies (WebGL, Native, Android, iOS, UWP). Events auto-dispatch to the main thread via SynchronizationContext.",
   "license": "MIT",
   "repository": {