Add container build for deployment

Standalone Next output, migration script run on start, storage volume
at /app/storage, port 4700. Database connection is created lazily so
the image builds without a database.

scripts/migrate.mjs

@@ -0,0 +1,18 @@
+import { migrate } from 'drizzle-orm/node-postgres/migrator'
+import { drizzle } from 'drizzle-orm/node-postgres'
+import pg from 'pg'
+
+const url = process.env.DATABASE_URL
+
+if (!url) {
+	console.error('[migrate] DATABASE_URL is required')
+	process.exit(1)
+}
+
+const pool = new pg.Pool({ connectionString: url, max: 1 })
+const db = drizzle(pool)
+
+console.log('[migrate] running logbuch migrations')
+await migrate(db, { migrationsFolder: './drizzle' })
+console.log('[migrate] done')
+await pool.end()