ImagineStill: rider _wip stills (xAI Imagine)

[jordanpartridge]

Parent

Asgard #128 (issues are the queue). kit#4 is the hook (Lexi requests, Kit fulfills) — do not close this by shipping stills. bikes-v2 #12 is the rider SKU. Design: docs/image-gen.md.

Story

Kit gets one stills hand. Default engine is xAI Imagine. v1 writes rider views to tools/models/rider/refs/_wip/ only. Lexi requests; Kit fulfills. Do not HTTP Lexi GenerateImage.

Job

PR-I2 in docs/image-gen.md. ImagineStill on KitAgent (16th tool; keep SoloAsk). catalog_id=rider, views front|side|back|ride, three-ref edit (<IMAGE_0> view, <IMAGE_1> sheet, <IMAGE_2> hero). Never overwrite sheet/hero. Never BoardWrite id=rider.

Done when

• Pest writes a JPEG under a temp rider refs root
• unknown catalog id errors
• rider without force_fresh does not call /generations
• three-ref edit fake body prompt contains <IMAGE_1>
• KitAgent contains ImagineStill and SoloAsk

Out of scope

• kit#4 GitHubOpenIssue
• VramOccupancy / stop-forge (I1)
• backend=forge (I4)
• PrintAgent, Meshy, logos, hallway #711

Chair

kit. Mouth-driven this month.

[jordanpartridge]

PR: #7