Bug: XHTTP transport not supported


**Problem:** 
`test_uris()` fails with EOF on VLESS+REALITY configs using XHTTP transport.

**Example config that fails:**
VLESS + REALITY + XHTTP

**Expected:** Should work like official Xray-core
**Actual:** Returns EOF / timeout

**Request:** Add XHTTP transport support to `core_engine.exe`

Please update the tester to support modern XHTTP transport.