OrcaRouter provider plugin (langextract-provider-orcarouter)

Describe the feature

Add an OrcaRouter provider plugin to the community registry. OrcaRouter is an OpenAI-compatible gateway that fronts models from multiple vendors through a single endpoint at https://api.orcarouter.ai/v1. It also runs gateway-level, zero-trust security for AI agents on the same endpoint — screening every prompt/response and governing every tool call on a default-deny basis, with no application code changes.

The plugin is implemented as an external LangExtract provider package (the recommended route from langextract/providers/README.md). It subclasses OpenAILanguageModel, so it inherits Chat Completions, JSON mode, structured outputs, and Batch API support. Model IDs starting with orcarouter/ (e.g. orcarouter/auto) route automatically.

• Package: langextract-provider-orcarouter
• Repo: https://github.com/JinhaoSong322/langextract-orcarouter
• Usage: lx.extract(..., model_id="orcarouter/auto", api_key=os.environ["ORCAROUTER_API_KEY"])
• Env keys: ORCAROUTER_API_KEY, ORCAROUTER_BASE_URL (default https://api.orcarouter.ai/v1)

Disclosure: I'm an engineer on the OrcaRouter team.