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/micromark-extension-gfm-strikethrough/lib/html.js

@@ -0,0 +1,26 @@
+/**
+ * @import {HtmlExtension} from 'micromark-util-types'
+ */
+
+/**
+ * Create an HTML extension for `micromark` to support GFM strikethrough when
+ * serializing to HTML.
+ *
+ * @returns {HtmlExtension}
+ *   Extension for `micromark` that can be passed in `htmlExtensions`, to
+ *   support GFM strikethrough when serializing to HTML.
+ */
+export function gfmStrikethroughHtml() {
+  return {
+    enter: {
+      strikethrough() {
+        this.tag('<del>');
+      }
+    },
+    exit: {
+      strikethrough() {
+        this.tag('</del>');
+      }
+    }
+  };
+}