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/prismjs/plugins/show-invisibles/prism-show-invisibles.css

@@ -0,0 +1,34 @@
+.token.tab:not(:empty),
+.token.cr,
+.token.lf,
+.token.space {
+	position: relative;
+}
+
+.token.tab:not(:empty):before,
+.token.cr:before,
+.token.lf:before,
+.token.space:before {
+	color: #808080;
+	opacity: 0.6;
+	position: absolute;
+}
+
+.token.tab:not(:empty):before {
+	content: '\21E5';
+}
+
+.token.cr:before {
+	content: '\240D';
+}
+
+.token.crlf:before {
+	content: '\240D\240A';
+}
+.token.lf:before {
+	content: '\240A';
+}
+
+.token.space:before {
+	content: '\00B7';
+}