srcdoc iframe — embedding artifacts without deploying

every artifact we built in claude needed a full netlify deploy just to show up as a live demo on the site. that meant converting to standalone html, pushing to a repo or hosting service, waiting for the deploy, then pasting the URL. for a project tracker that's supposed to move fast, that's too many steps.

the fix was simple. added an artifactHtml field to the firestore project schema — a string that holds raw html. when it's present, the embed frame switches from <iframe src={url}> to <iframe srcdoc={html}>. no deploy, no URL, no credits. paste the html into the admin form, save, done. the demo tab detects it automatically and shows "embedded artifact" in the toolbar instead of a URL. existing url-based embeds still work exactly as before.

firestore docs cap at 1MB. a typical claude artifact is 5-50KB. not even close to a problem. sandbox is allow-scripts only (no allow-same-origin) since it's inline html — slightly tighter security than the url-based embeds. built a terminal snake game as the first test artifact. green on dark, IBM Plex Mono, the whole aesthetic. about 8KB. also first time using claude code for the implementation — learned that worktree mode is confusing for beginners and should be off by default.