docs: add copilot instructions

.github/copilot-instructions.md

@@ -0,0 +1,24 @@
+# laravel-websockets
+
+## Overview
+WebSocket server for Laravel, Pusher-compatible. Ratchet-based, runs as a long-lived artisan command via supervisor.
+
+## Architecture
+- `src/Server/WebSocketHandler.php` — main Ratchet handler (onOpen/onMessage/onClose/onError)
+- `src/Websocket/Handler.php` — higher-level handler with app verification, channel management
+- `src/Server/Loggers/` — decorator loggers (HttpLogger, ConnectionLogger, WebSocketsLogger)
+- `src/Console/Commands/StartServer.php` — artisan command that boots the event loop
+
+## Logging
+- Auto-registers a `websocket` log channel (daily, `storage/logs/websocket.log`, 7-day retention)
+- `wsLog()` helper in WebSocketHandler for structured server-side logging
+- Logger base class persists to file via `fileLog()` in addition to console output
+
+## Configuration
+- PUSHER_APP_KEY should always be `websocket` — generic identifier, not environment-specific
+- Port 6001 (supervisor), Traefik terminates TLS in front
+- Config at `config/websockets.php`, apps defined via env vars
+
+## Conventions
+- Improvements go here (the package), not in consumer vendor/ folders
+- Commit, push, then `composer update` in the consumer project