feat: add dark theme header component with navigation

- Created HeaderDark component with responsive navigation including Cloud dropdown menu with breadcrumb-style display
- Implemented mobile menu with slide-out panel using Headless UI Dialog
- Integrated HeaderDark into HomeHostingDark page for consistent dark theme experience

src/components/HeaderDark.tsx

@@ -0,0 +1,181 @@
+import { useState } from 'react'
+import { Link, useLocation } from 'react-router-dom'
+import { Dropdown } from './ui/Dropdown'
+import { ChevronDownIcon } from '@heroicons/react/20/solid'
+import { Container } from './Container'
+import { Button } from './Button'
+import pmyceliumLogo from '../images/logos/logo_1.png'
+import { Dialog } from '@headlessui/react'
+import { Bars3Icon, XMarkIcon } from '@heroicons/react/24/outline'
+
+const cloudNavItems = [
+  { name: 'Cloud', href: '/cloud' },
+  { name: 'Compute', href: '/compute' },
+  { name: 'Storage', href: '/storage' },
+  { name: 'GPU', href: '/gpu' },
+]
+
+export function HeaderDark() {
+  const location = useLocation()
+  const [mobileMenuOpen, setMobileMenuOpen] = useState(false)
+
+  const getCurrentPageName = () => {
+    const currentPath = location.pathname;
+    if (currentPath.startsWith('/compute')) return 'Compute';
+    if (currentPath.startsWith('/storage')) return 'Storage';
+    if (currentPath.startsWith('/gpu')) return 'GPU';
+    return 'Cloud';
+  };
+
+  return (
+    <header className="bg-[#111111]">
+      <nav className="border-b border-gray-800">
+        <Container className="flex bg-transparent justify-between py-4">
+          <div className="relative z-10 flex items-center gap-16">
+            <Link to="/" aria-label="Home">
+              <img src={pmyceliumLogo} alt="Mycelium" className="h-8 w-auto" />
+            </Link>
+            <div className="hidden lg:flex lg:gap-10">
+              <Dropdown
+                buttonContent={
+                  <>
+                    {['Compute', 'Storage', 'GPU'].includes(getCurrentPageName()) ? (
+                      <>
+                        <span className="text-gray-400">Cloud {' >'} </span>
+                        <span className="text-white">{getCurrentPageName()}</span>
+                      </>
+                    ) : (
+                      <span className="text-white">Cloud</span>
+                    )}
+                    <ChevronDownIcon className="h-5 w-5 text-white" aria-hidden="true" />
+                  </>
+                }
+                items={cloudNavItems}
+              />
+              <Link
+                to="/network"
+                className="text-base/7 tracking-tight text-gray-300 hover:text-cyan-400 transition-colors"
+              >
+                Network
+              </Link>
+              <Link
+                to="/agents"
+                className="text-base/7 tracking-tight text-gray-300 hover:text-cyan-400 transition-colors"
+              >
+                Agents
+              </Link>
+              <Link
+                to="/pods"
+                className="text-base/7 tracking-tight text-gray-300 hover:text-cyan-400 transition-colors"
+              >
+                Pods
+              </Link>
+            </div>
+          </div>
+          <div className="flex items-center gap-6">
+            <div className="flex items-center gap-6 max-lg:hidden">
+              <Button
+                to="https://myceliumcloud.tf"
+                variant="outline"
+                as="a"
+                target="_blank"
+                rel="noopener noreferrer"
+              >
+                Deploy Now
+              </Button>
+              <Button to="/download" variant="solid" color="cyan">
+                Get Mycelium Connector
+              </Button>
+            </div>
+            <div className="lg:hidden">
+              <button
+                type="button"
+                className="-m-2.5 inline-flex items-center justify-center rounded-md p-2.5 text-gray-300 hover:text-cyan-400 transition-colors"
+                onClick={() => setMobileMenuOpen(true)}
+              >
+                <span className="sr-only">Open main menu</span>
+                <Bars3Icon className="h-6 w-6" aria-hidden="true" />
+              </button>
+            </div>
+          </div>
+        </Container>
+      </nav>
+      <Dialog as="div" className="lg:hidden" open={mobileMenuOpen} onClose={setMobileMenuOpen}>
+        <div className="fixed inset-0 z-10" />
+        <Dialog.Panel className="fixed inset-y-0 right-0 z-10 w-full overflow-y-auto bg-[#111111] px-6 py-6 sm:max-w-sm sm:ring-1 sm:ring-gray-200/10">
+          <div className="flex items-center justify-between">
+            <Link to="#" className="-m-1.5 p-1.5">
+              <span className="sr-only">Mycelium</span>
+              <img
+                className="h-8 w-auto"
+                src={pmyceliumLogo}
+                alt=""
+              />
+            </Link>
+            <button
+              type="button"
+              className="-m-2.5 rounded-md p-2.5 text-gray-300 hover:text-cyan-400 transition-colors"
+              onClick={() => setMobileMenuOpen(false)}
+            >
+              <span className="sr-only">Close menu</span>
+              <XMarkIcon className="h-6 w-6" aria-hidden="true" />
+            </button>
+          </div>
+          <div className="mt-6 flow-root">
+            <div className="-my-6 divide-y divide-gray-500/20">
+              <div className="space-y-2 py-6">
+                {cloudNavItems.map((item) => (
+                  <Link
+                    key={item.name}
+                    to={item.href}
+                    className="-mx-3 block rounded-lg px-3 py-2 text-base font-semibold leading-7 text-white hover:bg-gray-800"
+                    onClick={() => setMobileMenuOpen(false)}
+                  >
+                    {item.name}
+                  </Link>
+                ))}
+                <Link
+                  to="/network"
+                  className="-mx-3 block rounded-lg px-3 py-2 text-base font-semibold leading-7 text-white hover:bg-gray-800"
+                  onClick={() => setMobileMenuOpen(false)}
+                >
+                  Network
+                </Link>
+                <Link
+                  to="/agents"
+                  className="-mx-3 block rounded-lg px-3 py-2 text-base font-semibold leading-7 text-white hover:bg-gray-800"
+                  onClick={() => setMobileMenuOpen(false)}
+                >
+                  Agents
+                </Link>
+                <Link
+                  to="/pods"
+                  className="-mx-3 block rounded-lg px-3 py-2 text-base font-semibold leading-7 text-white hover:bg-gray-800"
+                  onClick={() => setMobileMenuOpen(false)}
+                >
+                  Pods
+                </Link>
+              </div>
+              <div className="py-6">
+                <Button
+                  to="https://myceliumcloud.tf"
+                  variant="outline"
+                  as="a"
+                  target="_blank"
+                  rel="noopener noreferrer"
+                  className="w-full"
+                  onClick={() => setMobileMenuOpen(false)}
+                >
+                  Start Deployment
+                </Button>
+                <Button to="/download" variant="solid" color="cyan" className="mt-4 w-full" onClick={() => setMobileMenuOpen(false)}>
+                  Get Mycelium Connector
+                </Button>
+              </div>
+            </div>
+          </div>
+        </Dialog.Panel>
+      </Dialog>
+    </header>
+  )
+}