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/mdn-data/css/syntaxes.schema.json

@@ -0,0 +1,15 @@
+{
+  "type": "object",
+  "additionalProperties": {
+    "type": "object",
+    "additionalProperties": false,
+    "required": [
+      "syntax"
+    ],
+    "properties": {
+      "syntax": {
+        "type": "string"
+      }
+    }
+  }
+}