refactor(repo): consolidate openflare-server to root and move subprojects to internal/apps

- Merge all files inside openflare-server to the repository root directory.
- Relocate agent, relay, and flared subprojects from internal/ to internal/apps/.
- Combine docker-compose files and update build context paths to root.
- Update GitHub workflows and Dockerfiles to refer to new directories and package names.
- Rewrite Go package imports across all files.
- Resolve database renew test race condition and clean up docs.

frontend/app/(main)/admin/layout.tsx

@@ -0,0 +1,18 @@
+"use client"
+
+import {AdminUsersProvider} from "@/contexts/admin-users-context"
+import {RequireAdminAuth} from "@/components/auth/require-auth"
+
+export default function AdminLayout({
+  children,
+}: {
+  children: React.ReactNode
+}) {
+  return (
+    <RequireAdminAuth>
+      <AdminUsersProvider>
+        {children}
+      </AdminUsersProvider>
+    </RequireAdminAuth>
+  )
+}