Add web adapter

This commit introduces a new web adapter, allowing applications to be
served in a web environment.

The web adapter provides functionality to create and manage application
instances, handle API requests, and serve the application via a fetch
handler. It also includes support for integrating with admin
functionalities when admin options are provided.

app/build.ts

@@ -340,6 +340,11 @@ async function buildAdapters() {
       platform: "node",
     }),
 
+    tsup.build({
+      ...baseConfig("web"),
+      platform: "neutral",
+    }),
+
     tsup.build({
       ...baseConfig("node"),
       platform: "node",