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/promise-limit/test/memoryUsageSpec.js

@@ -0,0 +1,48 @@
+/* eslint-env mocha */
+
+var times = require('lowscore/times')
+var limiter = require('..')
+var expect = require('chai').expect
+var max = require('./max')
+
+describe('promise-limit memory usage', function () {
+  var memoryProfile
+
+  beforeEach(function () {
+    memoryProfile = []
+  })
+
+  function checkMemory () {
+    var memory = process.memoryUsage().heapUsed
+    memoryProfile.push(memory)
+  }
+
+  function load (i) {
+    checkMemory()
+    return new Promise(function (resolve, reject) {
+      setTimeout(resolve, 10)
+    }).then(function () {
+      checkMemory()
+      var array = new Array(1024 * 1024)
+
+      return {
+        i: i,
+        array: array
+      }
+    })
+  }
+
+  it("doesn't use too much memory", function () {
+    this.timeout(20000)
+
+    var limit = limiter(5)
+    return Promise.all(times(1000, function (i) {
+      return limit(function () {
+        return load(i).then(function () {})
+      })
+    })).then(function () {
+      var maxMemoryUsage = max(memoryProfile)
+      expect(maxMemoryUsage).to.be.lessThan(2000 * 1024 * 1024)
+    })
+  })
+})