fix: Fix PostCSS config and Dockerfile

1. Rename postcss.config.js to postcss.config.cjs
   - Fixes CommonJS syntax in ES module project
   - Allows build to complete successfully

2. Remove --production flag from Dockerfile
   - Install ALL dependencies including sharp
   - Sharp required for Astro image optimization
   - Fixes sharp missing error

Both fixes enable successful Docker build and favicon to work.

easypanel.config.json

@@ -0,0 +1,16 @@
+{
+  "easypanel": {
+    "url": "",
+    "project": "customerwebsite",
+    "app": {
+      "name": "dealplustech-astro",
+      "port": 4321,
+      "image": "dealplustech-astro:latest"
+    },
+    "env": {
+      "NODE_ENV": "production",
+      "PORT": "4321",
+      "HOST": "0.0.0.0"
+    }
+  }
+}