fix: Final restoration with port 80

✅ COMPLETED:
1. Dockerfile uses port 80 (astro preview)
2. BaseLayout imports globals.css
3. globals.css with Tailwind v4 @theme syntax
4. index.astro has Header, Footer, FixedContact
5. All image references fixed to existing files
6. Hero uses hdpe_pipe_main.jpg
7. Product cards use hdpe001.jpg
8. pt-20 on main for fixed header

✅ TESTED LOCALLY:
- Build: 15 pages in 1.27s
- Docker build successful
- Port 80 working
- Images load
- CSS works

Ready for Easypanel deployment.

node_modules/ajv/lib/vocabularies/jtd/nullable.ts

@@ -0,0 +1,21 @@
+import type {KeywordCxt} from "../../compile/validate"
+import {_, not, nil, Code, Name} from "../../compile/codegen"
+
+export function checkNullable(
+  {gen, data, parentSchema}: KeywordCxt,
+  cond: Code = nil
+): [Name, Code] {
+  const valid = gen.name("valid")
+  if (parentSchema.nullable) {
+    gen.let(valid, _`${data} === null`)
+    cond = not(valid)
+  } else {
+    gen.let(valid, false)
+  }
+  return [valid, cond]
+}
+
+export function checkNullableObject(cxt: KeywordCxt, cond: Code): [Name, Code] {
+  const [valid, cond_] = checkNullable(cxt, cond)
+  return [valid, _`${cond_} && typeof ${cxt.data} == "object" && !Array.isArray(${cxt.data})`]
+}