fix: Fix product page syntax errors

1. Remove duplicate/broken code in product tables section
2. Fix PostCSS config for Tailwind 4
3. Add @tailwindcss/postcss dependency
4. Remove --production flag from Dockerfile (sharp required)

All fixes enable successful Docker build with favicon working.

node_modules/astro/dist/cli/build/index.d.ts

@@ -0,0 +1,6 @@
+import { type Flags } from '../flags.js';
+interface BuildOptions {
+    flags: Flags;
+}
+export declare function build({ flags }: BuildOptions): Promise<void>;
+export {};