Adapt for self-hosted deployment on Coolify

- Replace @vercel/postgres with standard pg library
- Add Dockerfile for Next.js standalone build
- Add tsconfig.json, postcss.config.js
- Fix globals.css undefined tailwind utilities
- Force dynamic rendering for DB-dependent pages
- Add .dockerignore

frontend/lib/db.ts

@@ -0,0 +1,16 @@
+import { Pool } from 'pg'
+
+const pool = new Pool({
+  connectionString: process.env.DATABASE_URL,
+})
+
+// Tagged template literal that mimics @vercel/postgres sql`` syntax
+export async function sql(strings: TemplateStringsArray, ...values: any[]) {
+  // Build parameterized query: replace template expressions with $1, $2, etc.
+  let text = strings[0]
+  for (let i = 0; i < values.length; i++) {
+    text += `$${i + 1}` + strings[i + 1]
+  }
+  const result = await pool.query(text, values)
+  return result
+}