Author a Rash scene

1. Locate the Rash repository and read web/core/model.js and docs/compatibility.md before editing. Confirm that the requested feature exists; distinguish current support from planned AVM compatibility.
2. Choose an existing preset and template, or call createProject('blank', preset). Use version 1 for scenes without symbols or version 2 with an explicit symbols array. Set unique IDs, dimensions, frame rate, frame duration, background, nodes, and script. Duration and keyframe positions are frame counts, not seconds.
3. Represent artwork with supported rect, ellipse, text, path, mesh, or symbol nodes. Use text content rather than HTML. Keep colors within the schema allowlist. Do not insert raw external SVG, script elements, event attributes, or remote resources.
4. Read docs/user-guide.md for shared graphic symbols, deterministic nested timelines, camera and mask authoring. Use web/core/symbols.js to construct definitions and instances. Never inline a symbol by guessing its timing. Add numeric keyframes to supported transform properties. Keep frames within 0..duration-1. Prefer a small retained SVG scene and reusable geometry over per-frame DOM replacement.
5. Call validateProject and sceneToSVG from current source. Save project JSON, then import it in the studio and verify playback, selection, undo, and export.
6. For interaction, read docs/runtime.md. Use only the bounded scripting grammar and supported scene commands. Do not claim full ActionScript compatibility. A requested unsupported feature requires an implementation and regression test or an explicit limitation.
7. Produce generated embed code through the studio export flow. Test from a separate host page. Keep worker/WASM URLs relative to the hosted embed distribution; never embed credentials.

Resolve rash://project/current, rash://node/<id>, rash://template/<id>, and rash://help/<topic> through web/core/resources.js. These are local addresses, not network endpoints or shell commands.

Run npm test and npm run test:ui for affected workflows. Report actual command results and any unverified browser feature. Publishing is separate from generating a project; follow the user's requested deployment scope.

For MCP authoring, use rash_project_get before rash_project_update, passing the returned revision as expectedRevision. On conflict, read again and reconcile; never silently overwrite. Use rash_render and rash_export with the stored revision. Project deletion is permanent. Local stdio projects and private hosted projects are separate stores; exchange validated JSON explicitly. UI metadata does not establish that a host has loaded the view.