feat: add Easypanel persistent volume support for Astro DB

- Change Dockerfile from nginx (static) to Node.js (SSR)
- Add @astrojs/node adapter for SSR mode
- Add OUT_DIR=/data for persistent SQLite storage
- Add .env.example with persistent storage config
- Update README with Easypanel deployment instructions
- Database persists across redeployments at /data/astro.db

skills/website-creator/templates/astro-tina-starter/astro.config.mjs

@@ -1,6 +1,7 @@
 import { defineConfig } from 'astro/config'
 import tailwindcss from '@tailwindcss/vite'
 import tina from 'tinacms'
+import node from '@astrojs/node'
 import { fileURLToPath } from 'url'
 import path from 'path'
 
@@ -27,7 +28,10 @@ export default defineConfig({
       },
     },
   },
-  output: 'static',
+  output: 'server',
+  adapter: node({
+    mode: 'standalone'
+  }),
   build: {
     assets: '_assets',
   },