**New "Anthropic-Compatible Endpoint" LLM provider** for self-hosted services that speak the Anthropic Messages API (`/v1/messages`) rather than the OpenAI chat-completions format. Select it under Settings → LLM, set `llm.anthropic_endpoint.url` (and an optional `llm.anthropic_endpoint.api_key` — keyless gateways are supported), and LDR builds a `ChatAnthropic` client pointed at your endpoint. The base URL is SSRF-validated before any request, and a real `ANTHROPIC_API_KEY` in the environment is never sent to a self-hosted endpoint. The official cloud Anthropic provider is unchanged.
