fix: add start script and nixpacks.toml for Dokploy deployment

nixpacks.toml

@@ -0,0 +1,10 @@
+[variables]
+NODE_ENV = "production"
+HOST = "0.0.0.0"
+PORT = "4321"
+
+[phases.setup]
+nixPkgs = ["nodejs_20"]
+
+[start]
+cmd = "node ./dist/server/entry.mjs"

package.json

@@ -6,6 +6,7 @@
   "scripts": {
     "dev": "astro dev",
     "build": "astro build",
+    "start": "node ./dist/server/entry.mjs",
     "preview": "astro preview",
     "check": "astro check"
   },