fix(eden): resolve server/client detection and bundler issues

- Use typeof window === undefined for standard Next.js server detection
- Use NEXT_PUBLIC_SITE_URL env var instead of hardcoded localhost:3000
- Use require() for server branch to prevent Elysia from entering client bundle
- Add type assertion on require() to preserve Eden Treaty types

lib/eden.ts

@@ -1,7 +1,10 @@
 import { treaty } from "@elysia/eden"
-import { app } from "@/app/api/[[...slugs]]/route"
+import type { App } from "@/app/api/[[...slugs]]/route"
 
+// Use require() on the server branch to prevent the client bundler from
+// pulling in Elysia and the route module. The typeof window check is the
+// standard Next.js server-vs-client guard.
 export const api =
-  typeof process !== "undefined"
+  typeof window === "undefined"
-    ? treaty(app).api
+    ? treaty((require("../../app/api/[[...slugs]]/route") as { app: App }).app).api
-    : treaty<typeof app>("localhost:3000").api
+    : treaty<App>(process.env.NEXT_PUBLIC_SITE_URL || "http://localhost:3000").api