cloudflare: enable fs with @cloudflare/vite-plugin (#239)

* init dev vite write plugin

* reorganized cf proxy, fixed dev write

examples/cloudflare-worker/config.ts

@@ -1,7 +1,21 @@
 import type { CloudflareBkndConfig } from "bknd/adapter/cloudflare";
+import { syncTypes } from "bknd/plugins";
+import { writeFile } from "node:fs/promises";
+
+const isDev = !import.meta.env.PROD;
 
 export default {
    d1: {
       session: true,
    },
+   options: {
+      plugins: [
+         syncTypes({
+            enabled: isDev,
+            write: async (et) => {
+               await writeFile("bknd-types.d.ts", et.toString());
+            },
+         }),
+      ],
+   },
 } satisfies CloudflareBkndConfig;