Additional Eject Presets

Parent epic: #1055 Blocked by: #2185 ## Context After the canonical Default and Minimal on-demand Video Skins are released through #2185, extend the proven Eject pipeline to audio, live, and background presets. These presets should reuse the same canonical catalog, framework/style outputs, parity gates, Shadcn and CLI delivery boundaries where applicable, documentation process, and release discipline established by the Video milestone. ## Scope Track focused delivery epics for: - Default and Minimal audio. - Default and Minimal live video and live audio. - Background presentation. ## Acceptance criteria - [ ] Each follow-up preset has an explicit canonical component and composition boundary. - [ ] Shared Video components are reused where behavior is identical. - [ ] Preset-specific components and styles are added only where product behavior differs. - [ ] React/HTML and Tailwind/vanilla CSS follow the released delivery path. - [ ] Public source delivery uses the established catalog, registry, and Eject CLI boundaries where supported. - [ ] Each preset has its own parity evidence, documentation, and release verification before legacy removal. ## Sequencing Begin implementation after #2185 releases the canonical on-demand Video milestone.