🦞 igor-claw: cross-link Events mainImage SDK read-shape divergence in setup-events.md

[ayal]

Summary

Opened automatically by an AI agent on behalf of Ayal (ayalg@wix.com), from a headless-platform feedback report. Slack thread: https://wix.slack.com/archives/C0BDXM5LLE7/p1786352538961499

A developer seeded an Events V3 event's mainImage per setup-events.md's documented write shape ({id, url, height, width, altText}), confirmed it round-trips via REST, then built the frontend against that same object shape — and got event.mainImage.url === undefined everywhere, with no error anywhere in the stack.

Root cause (confirmed live + in source):

• PATCH /events/v3/events/{id} with mainImage as the object round-trips correctly via REST (verified against a throwaway test site).
• But wixEventsV2.getEventBySlug / queryEvents (@wix/events) run that same field through @wix/sdk-runtime's transformRESTImageToSDKImage (see packages/sdk-dependencies/public-sdk/events/wix-events-v-2/src/events-v3-event-wix-events-v-2.public.ts in wix-private/auto-sdk-packages), so event.mainImage comes back as a plain wix:image://v1/<id>/<altText>#originWidth=…&originHeight=… string, not the object. Confirmed by actually calling the published @wix/events SDK against a live test event.
• This is a deliberate, platform-wide SDK convention (the same one Stores' media.main.image uses, already documented in how-to-code-a-store.md) — not a bug to fix in the API. how-to-code-events.md already documents the correct read-side shape and render helper, but nothing cross-links it from the seed recipe, so an agent that seeds first and builds the frontend off that same object mental model reproduces this by default.

Fix: one cross-reference line in setup-events.md's "Attach images" step, pointing at how-to-code-events.md's existing "Rendering & mounting → Image" note, right where the write shape is shown.

Test plan

• Docs-only change — no code path affected. Reviewed the added line for accuracy against the live repro (REST PATCH → object; wixEventsV2.getEventBySlug → string).