Adds docs/canvases-launch.md as a 2-minute pitch readers can share in
slack. Covers: what canvases are, the 30-second try-it-locally recipe,
the 4 renderer types with payload shapes, empty / mobile states, the
extensibility contract, the deliberately-deferred items, and the 18
corner-case fixes that came out of 12 codex review passes.
Hero / empty-state / mobile screenshots copied out of the gitignored
.gstack/qa-reports/ into docs/assets/canvases/ so they survive locally
and on GitHub.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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