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/runtime/server/render/instruction.js

@@ -0,0 +1,13 @@
+const RenderInstructionSymbol = Symbol.for("astro:render");
+function createRenderInstruction(instruction) {
+  return Object.defineProperty(instruction, RenderInstructionSymbol, {
+    value: true
+  });
+}
+function isRenderInstruction(chunk) {
+  return chunk && typeof chunk === "object" && chunk[RenderInstructionSymbol];
+}
+export {
+  createRenderInstruction,
+  isRenderInstruction
+};