M0 — wisp renderer

21 chunks delivered the renderer: Stage, transforms, sprites, graphics, text, filters, mesh. The visual evidence lives in its own book:

→ Wisp stories — every chunk's renderable output, with the SDF / batching / mask / text-pipeline deep dives.

→ Wisp overview — the public API tour: Container, Sprite, Graphics, Text, RenderTexture, the filter chain, the mask system.

For the chunk-level acceptance criteria and "Done when:" history, see _docs/milestone-0-renderer.md in the repo (kept as engineering record, not published to the book).