Merge main into feat/voice-outlines

Adopts main's loadBundledJson(url, {signal}) and builds the Census and
Who's On First pack URLs when they are read, not at import.

build/vite.js

@@ -1,5 +1,50 @@
 import { applicationHtmlPlugin } from './application-html.js';
 import cesium from 'vite-plugin-cesium';
+import { DEFAULT_ALLOWED_HOSTS, hostCheckPlugin } from './allowedHosts.js';
+import { embedFramingPlugin } from './embed-framing.js';
+import { panelBuildPlugin } from './panel.js';
+
+/**
+ * Content-Security-Policy for every document the dev/preview server serves.
+ * No inline script is permitted, and the only foreign script origins are the
+ * three that the Bhote Koshi event's embedded media needs (YouTube, Facebook
+ * and X), which frame-src matches for their players and posts. 'unsafe-eval' is
+ * required: Knockout (bundled inside @cesium/widgets) resolves the global
+ * object with `(0, eval)("this")` at module load, and without it the Cesium
+ * widget never initializes (verified in headless Chrome). It also covers
+ * Cesium's WASM decoders. `blob:` is required in the built app: Cesium's
+ * bundled workers bootstrap through `importScripts(blob:...)`, which a worker
+ * checks against script-src (the dev server loads them by URL instead).
+ * Widen any other directive only for a real violation.
+ */
+export const BROWSER_CSP = [
+  "default-src 'self'",
+  // The Bhote Koshi event's embedded media: the YouTube player API, the
+  // Facebook video SDK and X's post widget (src/data/bhoteKoshiEmbeddedMedia.js).
+  "script-src 'self' 'unsafe-eval' blob: https://www.youtube.com https://connect.facebook.net https://platform.twitter.com",
+  "style-src 'self' 'unsafe-inline' https://fonts.googleapis.com",
+  "font-src 'self' data: https://fonts.gstatic.com",
+  "img-src 'self' data: blob: https:",
+  "media-src 'self' blob: https:",
+  "connect-src 'self' blob: data: https: wss: ws:",
+  "worker-src 'self' blob:",
+  "child-src 'self' blob:",
+  // The same media's players and posts, which load in frames.
+  "frame-src 'self' blob: https://www.youtube-nocookie.com https://www.youtube.com https://www.facebook.com https://platform.twitter.com",
+  "manifest-src 'self'",
+  "object-src 'none'",
+  "base-uri 'self'",
+  "form-action 'self'",
+  "frame-ancestors 'none'",
+].join('; ');
+
+/** Response headers shared by the dev and preview servers. */
+export const BROWSER_HEADERS = Object.freeze({
+  'X-Frame-Options': 'DENY',
+  'Content-Security-Policy': BROWSER_CSP,
+  // Responses are only ever used as the type the server declares.
+  'X-Content-Type-Options': 'nosniff',
+});
 
 /** Build browser assets with explicit inputs; never load environment or providers. */
 export function createBrowserViteConfig({
@@ -10,10 +55,19 @@ export function createBrowserViteConfig({
   photonUrl,
   host = 'localhost',
   port = 4173,
+  allowedHosts = DEFAULT_ALLOWED_HOSTS,
   command,
 } = {}) {
   return {
-    plugins: [cesium(), applicationHtmlPlugin(), ...plugins],
+    plugins: [
+      // First, so no provider route answers a Host the server does not allow.
+      hostCheckPlugin(),
+      cesium(),
+      applicationHtmlPlugin(),
+      ...plugins,
+      embedFramingPlugin(),
+      panelBuildPlugin(),
+    ],
     ...(publicDir === undefined ? {} : { publicDir }),
     // A production build must not clean the dependency cache a running dev
     // server is still serving optimized module URLs from.
@@ -32,19 +86,22 @@ export function createBrowserViteConfig({
     server: {
       host: host || 'localhost',
       port: parseInt(port, 10) || 4173,
-      allowedHosts:
-        host === '0.0.0.0' || host === '::'
-          ? true
-          : ['localhost', '127.0.0.1', '.local'],
+      // A wildcard bind only chooses interfaces; it never disables Vite's
+      // Host-header check. LAN hostnames are added explicitly (see
+      // build/allowedHosts.js); IP addresses are always accepted.
+      allowedHosts: [...allowedHosts],
       fs: {
         deny: ['.env', '.env.*', '*.{crt,pem}', '**/.git/**', '**/ENVIRONMENT'],
       },
-      // These headers protect the document containing Provider Settings.
-      headers: {
-        'X-Frame-Options': 'DENY',
-        'Content-Security-Policy': "frame-ancestors 'none'",
-      },
+      // These headers protect the document containing Provider Settings and
+      // give the whole page a real Content-Security-Policy (BROWSER_CSP).
+      // Embed-mode documents are framable instead: embed-framing.js rewrites
+      // only the frame-ancestors directive and keeps the rest of the policy.
+      headers: BROWSER_HEADERS,
     },
+    // The preview server serves the same documents, so it carries the same
+    // framing + CSP hardening (one constant, no drift).
+    preview: { headers: BROWSER_HEADERS },
     define: {
       'import.meta.env.GOOGLE_MAPS_API_KEY': JSON.stringify(googleApiKey),
       'import.meta.env.CESIUM_ION_TOKEN': JSON.stringify(cesiumToken),