docs: Document Dual Transport Architecture (SSE and WS) in instructions

instructions.md

@@ -111,3 +111,10 @@ When instructed to restart, update, or stop the mcp-memory-server binary, never
 - How: Always use the built-in graceful shutdown mechanisms:
   1. CLI Flag: mcp-memory-server --exit (or --restart)
   2. HTTP Endpoint: POST http://127.0.0.1:3000/shutdown
+
+## 14. Dual Transport Architecture (SSE & WebSockets)
+- **Constraint:** The MCP Memory Server natively supports a dual transport layer. You MUST maintain both if modifying network code.
+  - **SSE (/sse & /messages):** Used strictly by the Antigravity LLM client because standard AI runtimes prefer synchronous HTTP JSON-RPC wrappers.
+  - **WebSockets (/ws):** Used strictly by external UI clients (e.g., dashboard.html) or the mcp-memory-stub proxy.
+- **Behavior:** Both transport layers route into the exact same central handle_request pipeline. Do not build feature logic that only works on one transport protocol.
+