Load the God's Eye View panel through the MCP server

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.

package.json

@@ -41,6 +41,7 @@
     "dev:secure": "./scripts/dev-secure.sh",
     "opensky:import": "./scripts/opensky-import-client.sh",
     "build": "vite build",
+    "build:panel": "node scripts/build-panel.mjs",
     "preview": "vite preview",
     "test": "node scripts/run-unit-tests.mjs",
     "test:track": "node scripts/track-regression.mjs",