Adds OpenAI-compatible image_url content blocks to the chat message
model, wiring attached images through build_chat_messages_with_reasoning
as multimodal user-content arrays. When images are present, user
messages emit a content array of text + image_url parts instead of a
plain string, matching the OpenAI vision API shape.
- models.rs: new ImageUrlContent struct, ContentBlock::ImageUrl variant
- client/chat.rs: image_parts collection, multimodal wire format for
user messages, image-aware message inspection, stream-event no-op
- Exhaustiveness arms added across 10 files (compaction, seam_manager,
capacity_flow, purge, notifications, session_picker, utils,
working_set, rlm/session, runtime_api)
- Test: request_builder_emits_openai_image_url_parts_for_user_images
Credit: @xyuai (PR #2587 — root cause + initial implementation)
Closes: #2584
Co-authored-by: xyuai <xyuai@users.noreply.github.com>
Hunter Bown
dd26114697