✨ refactor: streamline SSR setup and remove Babel configuration

- Updated import path for app.server module in SSR hook.
- Removed babel.config.server.json as Babel is no longer needed for async/await transformation.
- Adjusted esbuild configuration to target ESNext and modified output paths.
- Enhanced App.svelte to handle initial content loading during SSR.
- Updated SSR script to load messages synchronously before rendering.
- Simplified build:server script in package.json by removing Babel step.

api/hooks/ssr/get_read.js

@@ -4,6 +4,7 @@ const { release } = require("../config-client")
 
 const { ssrValidatePath } = require("../config")
 const { ssrRequest } = require("../lib/ssr-server")
+const APP_SERVER_MODULE_PATH = "../lib/app.server"
 ;(function () {
     var request = context.request()
 
@@ -128,7 +129,7 @@ const { ssrRequest } = require("../lib/ssr-server")
             try {
                 // if error, output plain html without prerendering
                 // @ts-ignore
-                const app = require("../lib/app.server")
+                const app = require(APP_SERVER_MODULE_PATH)
 
                 const rendered = app.default.render({
                     url: url,