refactor: add prefix to relative assets

refactor: add prefix to server entrypoints
refactor: add prefix to express router
refactor: add prefix to router basename

apps/server/src/externals.ts

@@ -3,7 +3,8 @@
  */
 
 import { readFileSync, writeFileSync } from 'node:fs';
-import { resolve } from 'node:path';
+
+import { srcFiles } from './setup/index.js';
 
 // =================================================
 // resolve running environment
@@ -19,19 +20,20 @@ export const isProduction = isDocker || (env === 'production' && !isTest);
  * This is only needed in the cloud environment where the client is not at the root segment
  * ie: https://cloud.getontime.com/client-hash/timer
  */
-export function updateRouterPrefix(prefix: string | undefined = process.env.ROUTER_PREFIX) {
+export function updateRouterPrefix(prefix: string | undefined = process.env.ROUTER_PREFIX): string {
   if (!prefix) {
-    return;
+    return '';
   }
 
-  const indexFile = resolve('.', 'client', 'index.html');
   try {
-    const data = readFileSync(indexFile, { encoding: 'utf-8', flag: 'r' }).replace(
-      /<base href="[^"]*">/g,
-      `<base href="${prefix}" />`,
+    const data = readFileSync(srcFiles.clientIndexHtml, { encoding: 'utf-8', flag: 'r' }).replace(
+      '<base href="/" />',
+      `<base href="/${prefix}/" />`,
     );
-    writeFileSync(indexFile, data, { encoding: 'utf-8', flag: 'w' });
+    writeFileSync(srcFiles.clientIndexHtml, data, { encoding: 'utf-8', flag: 'w' });
   } catch (_error) {
     /** unhandled */
   }
+
+  return `/${prefix}`;
 }