v1.5.1 — fix Cloudflare llama-3.2 vision silent empty response

Fixed

• analyzeImage() silent empty response on Cloudflare — @cf/meta/llama-3.2-11b-vision-instruct via the Workers AI binding requires a raw { image: number[], prompt, max_tokens } input shape, not the OpenAI-compatible messages/image_url format. The chat path returns choices[0].message.content === null via the binding, causing extractText() to silently return "". The provider now detects this model and dispatches to the raw binding format. Other vision models are unaffected. Fixes #53.

Full changelog: https://github.com/Stackbilt-dev/llm-providers/blob/main/CHANGELOG.md