Product-idea preset and local drafts
Preset 2: Product idea (product-idea). A central ellipse "Product idea" connects outwards to four rectangles: target users, core value, key flow, risks & validation, plus the Chinese title — 15 elements total, with arrows carrying startBinding/endBinding. Useful for brainstorming before a requirements meeting.
Local draft semantics: (1) off by default, state().enabled=false, save() returns persisted:false / DRAFT_DISABLED with zero writes; (2) after an explicit enable(), save(scene) writes only al:draw:v1:scene and :savedAt; (3) after a reload, restore() returns status=restored with the same 15 elements; (4) disable() deletes every al:draw:v1:* key and later saves again return DRAFT_DISABLED; (5) clearOnlySiteKeys() touches only our keys and leaves other sites intact.
Safety: files in imported documents (remote images) are dropped and never fetched; image elements are rejected by validation; arbitrary SVG text is scanned by scanSvgThreats but remains download-only, and sanitizeSvgForDom() always returns injectIntoDom=false. The canvas has no ads and no Firebase / collaboration / Plus / official-account entries; the 48px brand bar is a semantic banner, toolbar targets are ≥44px, and browser-back gestures are not captured (gestureDecision() returns allowBrowserBack=true).
The runtime request allowlist contains only same-origin assets / site.json / version.json / healthz and local blob: URLs; official service hosts, WebSockets and external schemes are rejected, and audit logs record index + reason only, never the URL.