* feat(tools): implement image reference processing and native provider support
- Support OpenAI image edits via both Multipart form-data and JSON payloads
- Automatically append reference image descriptions to prompt under [Reference Image Roles]
- Support downloading image URLs for Gemini native image generation
- Deduplicate reference images to optimize API request size
- Add unit tests for Codex, DashScope, MiniMax, BytePlus and local/remote path resolution
* fix(tools): SSRF-guard reference-image URL downloads in create_image
downloadImageBytes fetched caller-supplied ref_images[].url with a plain
http.Client and unbounded io.ReadAll — no SSRF validation, redirect
policy, or size cap, letting the gateway dial loopback/private/metadata
hosts or read arbitrarily large responses.
- Validate the URL via security.Validate and pin the resolved IP, then
download through security.NewSafeClient (pinned dial, no redirects).
- Cap the response with a bounded read (refImageMaxBytes, 20 MB).
- Reject non-HTTP(S) reference URLs up front (file://, data:, gopher://)
so provider-forwarded URLs stay HTTP(S)-only; document the trust
boundary between gateway-side fetch and provider-forwarded URLs.
- Add regression tests: blocked loopback/private/metadata, unfollowed
redirect, oversized response, and non-http(s) scheme rejection.
