folk-prompt can now spawn shapes on the canvas when Tools mode is
enabled. Gemini calls functions (create_map, create_note, create_embed,
create_image, create_bookmark, create_image_gen) and the client
executes them via window.__canvasApi. Multi-turn loop on server (max 5
rounds) with synthetic success responses. Extensible via registerCanvasTool().
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
