Add admin-core frontend (Port 3008)

Next.js admin frontend for Core with 3 categories
(Communication, Infrastructure, Development), 13 modules,
2 roles (developer, ops), and 11 API proxy routes.
Includes docker-compose service and nginx SSL config.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

admin-core/components/common/Breadcrumbs.tsx

@@ -0,0 +1,65 @@
+'use client'
+
+import Link from 'next/link'
+import { usePathname } from 'next/navigation'
+import { navigation, metaModules, getModuleByHref, getCategoryById, CategoryId } from '@/lib/navigation'
+
+export function Breadcrumbs() {
+  const pathname = usePathname()
+
+  const items: Array<{ label: string; href: string }> = []
+
+  items.push({ label: 'Dashboard', href: '/dashboard' })
+
+  const pathParts = pathname.split('/').filter(Boolean)
+
+  if (pathParts.length > 0) {
+    const categoryId = pathParts[0] as CategoryId
+    const category = getCategoryById(categoryId)
+
+    if (category) {
+      items.push({ label: category.name, href: `/${category.id}` })
+
+      if (pathParts.length > 1) {
+        const moduleHref = `/${pathParts[0]}/${pathParts[1]}`
+        const result = getModuleByHref(moduleHref)
+        if (result) {
+          items.push({ label: result.module.name, href: moduleHref })
+        }
+      }
+    } else {
+      const metaModule = metaModules.find(m => m.href === `/${pathParts[0]}`)
+      if (metaModule && metaModule.href !== '/dashboard') {
+        items.push({ label: metaModule.name, href: metaModule.href })
+      }
+    }
+  }
+
+  if (items.length <= 1) {
+    return null
+  }
+
+  return (
+    <nav className="flex items-center gap-2 text-sm text-slate-500 mb-4">
+      {items.map((item, index) => (
+        <span key={`${index}-${item.href}`} className="flex items-center gap-2">
+          {index > 0 && (
+            <svg className="w-4 h-4 text-slate-300" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" />
+            </svg>
+          )}
+          {index === items.length - 1 ? (
+            <span className="text-slate-900 font-medium">{item.label}</span>
+          ) : (
+            <Link
+              href={item.href}
+              className="hover:text-primary-600 transition-colors"
+            >
+              {item.label}
+            </Link>
+          )}
+        </span>
+      ))}
+    </nav>
+  )
+}