refactor(mcp): strip sse fallback architecture in favor of pure websockets and fix nvim NDJSON bug

instructions.md

@@ -112,14 +112,6 @@ When instructed to restart, update, or stop the mcp-memory-server binary, never
   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.
-
-
-
 ## 15. Neovim Integration & God Mode
 The project contains two MCP binaries (win-nvim and linux-nvim) that bridge JSON-RPC over stdio directly to the active Neovim instance (using ctive_nvim.txt for Last Focused Wins telemetry). 
 - These binaries expose basic tools (