Xiaozhi-esp32-server-java through 6.1.0 Authentication Bypass via OTA Endpoint Token Issuance

Xiaozhi-esp32-server-java through 6.1.0 contains an authentication bypass vulnerability that allows unauthenticated attackers to obtain valid device WebSocket tokens by requesting /api/device/ota with any MAC address. Attackers can open a victim device's WebSocket channel to read private role system prompts, write conversation history, consume LLM/STT/TTS credentials, and overwrite device metadata.