Shim window.process for CDN-loaded host bundle

mountHost's chunk references process.env.NODE_ENV expecting a
bundler-time substitution that doesn't happen when the file is loaded
raw from jsdelivr. Crashes on first execution with "process is not
defined". Tiny shim assigned before the module imports clears it.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

index.html

@@ -46,6 +46,22 @@
         })();
     </script>
 
+    <!-- `process` shim for CDN-loaded ESM.
+         The host bundle (`host/dist/entry/auto.js`) was built expecting
+         a downstream bundler (Vite/Rollup) to substitute `process.env.NODE_ENV`
+         at build time. Loaded raw from jsdelivr that substitution never
+         happens, and the chunk crashes on first reference with
+         `ReferenceError: process is not defined`. A tiny shim assigned
+         BEFORE the module imports run resolves it. The double-`??=` keeps
+         us a polite citizen in case any later loader brings a real `process`.
+         (We DON'T need this when using a bundler — see the `dashboard/`
+         sibling app, where Vite handles the substitution.) -->
+    <script>
+        globalThis.process ??= { env: {} };
+        globalThis.process.env ??= {};
+        globalThis.process.env.NODE_ENV ??= 'production';
+    </script>
+
     <!-- Pre-paint visibility gate. Both paths start with #mainApp hidden:
            - Standalone: mountHost() owns the page; #mainApp stays hidden.
            - Embed: #mainApp is revealed by the embed handler once