Subscribe to SignalR Position.z and CarData.z, decode DEFLATE payloads, stream throttled positions over SSE, and render live car dots against cached track outline bounds with tap telemetry.
Alignment spike: no checked-in or locally cached real Position.z samples were available in this isolated worktree; verified both streams expose the official raw F1 X/Y/Z coordinate contract and implemented shared-bounds normalization against prefetched OpenF1 outlines. Fallback build-outline-from-stream was not taken.
Playwright remains out of scope for live rendering because BOXBOX_DISABLE_LIVE is used there; coverage is via parser, web handler/SSE, pure transform, and seeded component tests.
