Images and stylesheet files load as data: URLs, which hosts allow where
some refuse blob: images; the scene-asset source gets an https app
address the panel serves, since Codex pages use their own scheme; and a
panel whose 3D context the browser takes back says so.
Hosts serve panels from their own sites and may refuse other addresses;
Codex refuses any address on the user's machine. The panel now never
requests the app's server: it loads the app's panel build and data
through panel_request, a tool only the panel may call, which requests
the path from the app's server. One path in every host; only map
providers load directly.
npm run build:panel writes the panel build to dist/panel, served at
/panel/: one app script, one stylesheet, Cesium's script, and Cesium's
workers as one script Cesium runs from memory. Tools may now be marked
app-only. The panel CORS rules are gone.
Sameh Khamis