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/utils.js

@@ -0,0 +1,20 @@
+import fs from "node:fs/promises";
+const frontmatterRE = /^---(.*?)^---/ms;
+async function loadId(pluginContainer, id) {
+  const result = await pluginContainer.load(id, { ssr: true });
+  if (result) {
+    if (typeof result === "string") {
+      return result;
+    } else {
+      return result.code;
+    }
+  }
+  try {
+    return await fs.readFile(id, "utf-8");
+  } catch {
+  }
+}
+export {
+  frontmatterRE,
+  loadId
+};