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/src/adapter/web/web.adapter.ts

@@ -0,0 +1,47 @@
+import {
+   createFrameworkApp,
+   createRuntimeApp,
+   type FrameworkBkndConfig,
+} from "bknd/adapter";
+import type { AdminControllerOptions } from "modules/server/AdminController";
+import type { App } from "App";
+
+export type WebBkndConfig<Env = any> = FrameworkBkndConfig<Env> & {
+   adminOptions?: AdminControllerOptions | false;
+};
+
+export function createBknd<Env>(config: WebBkndConfig<Env>, args?: Env) {
+   let appPromise: Promise<App> | undefined;
+
+   const { adminOptions, ...frameworkConfig } = config;
+
+   async function getApp() {
+      if (!appPromise) {
+         if (adminOptions != null) {
+            appPromise = createRuntimeApp({ ...frameworkConfig, adminOptions }, args);
+         } else {
+            appPromise = createFrameworkApp(frameworkConfig, args);
+         }
+      }
+      return appPromise;
+   }
+
+   async function getApi(opts?: { headers?: Headers; verify?: boolean }) {
+      const app = await getApp();
+      if (opts?.verify) {
+         const api = app.getApi({ headers: opts.headers });
+         await api.verifyAuth();
+         return api;
+      }
+      return app.getApi();
+   }
+
+   function serve() {
+      return async (req: Request) => {
+         const app = await getApp();
+         return app.fetch(req);
+      };
+   }
+
+   return { getApp, getApi, serve };
+}