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/retext/index.d.ts

@@ -0,0 +1,10 @@
+/// <reference types="retext-latin" />
+
+import type {Root} from 'nlcst'
+import type {Processor} from 'unified'
+
+/**
+ * Create a new unified processor that already uses `retext-latin` and
+ * `retext-stringify`.
+ */
+export const retext: Processor<Root, undefined, undefined, Root, string>