refactor: Move Astro to root, use PORT env (default 80), allow all hosts

- Move Astro files from dealplustech-astro/ to project root
- Update Dockerfile: PORT environment variable (default 80)
- Add vite.config.ts with allowedHosts: true
- Matches nixpacks behavior for Easypanel deployment
- No hardcoded ports or domains

node_modules/astro/dist/vite-plugin-astro-server/trailing-slash.js

@@ -0,0 +1,34 @@
+import {
+  collapseDuplicateTrailingSlashes,
+  hasFileExtension,
+  isInternalPath
+} from "@astrojs/internal-helpers/path";
+import { trailingSlashMismatchTemplate } from "../template/4xx.js";
+import { writeHtmlResponse, writeRedirectResponse } from "./response.js";
+function trailingSlashMiddleware(settings) {
+  const { trailingSlash } = settings.config;
+  return function devTrailingSlash(req, res, next) {
+    const url = new URL(`http://localhost${req.url}`);
+    let pathname;
+    try {
+      pathname = decodeURI(url.pathname);
+    } catch (e) {
+      return next(e);
+    }
+    if (isInternalPath(pathname)) {
+      return next();
+    }
+    const destination = collapseDuplicateTrailingSlashes(pathname, true);
+    if (pathname && destination !== pathname) {
+      return writeRedirectResponse(res, 301, `${destination}${url.search}`);
+    }
+    if (trailingSlash === "never" && pathname.endsWith("/") && pathname !== "/" || trailingSlash === "always" && !pathname.endsWith("/") && !hasFileExtension(pathname)) {
+      const html = trailingSlashMismatchTemplate(pathname, trailingSlash);
+      return writeHtmlResponse(res, 404, html);
+    }
+    return next();
+  };
+}
+export {
+  trailingSlashMiddleware
+};