docs(bg,en): fix ports and WebSocket example for new server model

- Update architecture diagram to include WebSocket server (port 9913)
- Fix HTTP port from 9470 to 9912 (TCP + 440) in protocol docs
- Fix WebSocket port from 9471 to 9913 (TCP + 441) in protocol docs
- Fix WebSocket Nim example: remove non-existent onMessage API and
  unsafe cast[string](data), use correct WsServer API with safe helpers
- Clarify TCP_NODELAY is also handled internally by hunos (HTTP)
- Note that bytesToString/stringToBytes are wire-protocol helpers

docs/bg/protocol.md

@@ -110,7 +110,7 @@ BaraDB поддържа множество протоколи за клиент
 
 ## HTTP/REST API
 
-Базов URL: `http://localhost:9470/api/v1`
+Базов URL: `http://localhost:9912/api/v1` (HTTP порт = TCP порт + 440)
 
 ### Rate Limiting
 
@@ -271,7 +271,7 @@ POST /admin/check
 
 ## WebSocket Протокол
 
-URL: `ws://localhost:9471`
+URL: `ws://localhost:9913` (WebSocket порт = TCP порт + 441)
 
 ### Формат на Frame
 
@@ -301,7 +301,7 @@ WebSocket текстови frame-ове съдържат JSON съобщения
 ### Pub/Sub Пример
 
 ```javascript
-const ws = new WebSocket('ws://localhost:9471');
+const ws = new WebSocket('ws://localhost:9913');
 
 ws.onopen = () => {
   // Абониране за промени в таблица