Admin panel (warp-admin) and the apps/ui design system

apps/ui: Warp's design system for Vue 3 + Tailwind v4. Tokens, fonts,
icons and logo come from the brand package, with a Tailwind theme on the
tokens and Vue components on the brand component styles.

apps/admin: the admin panel as a separate, optional service. warp-admin
embeds the built Vue app and proxies only the login endpoints and
/_warp/admin/v1 to the homeserver. Pages: dashboard, users, rooms,
federation, registration and tokens, server notices, application
services, audit log.

Also: pnpm workspace, go.work entry, Dockerfile, an `admin` compose
profile, Makefile targets, a CI job with a proxy smoke test, and docs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/ui/src/components/WIconButton.vue

@@ -0,0 +1,28 @@
+<script setup lang="ts">
+import WIcon from './WIcon.vue'
+import type { IconName } from '../icons'
+
+withDefaults(
+  defineProps<{
+    icon: IconName
+    /** Required accessible name, also the tooltip. */
+    label: string
+    variant?: 'ghost' | 'solid'
+    type?: 'button' | 'submit'
+    disabled?: boolean
+  }>(),
+  { variant: 'ghost', type: 'button', disabled: false },
+)
+</script>
+
+<template>
+  <button
+    :type="type"
+    :class="['wp-iconbtn', variant === 'solid' && 'wp-iconbtn-solid']"
+    :aria-label="label"
+    :title="label"
+    :disabled="disabled"
+  >
+    <WIcon :name="icon" />
+  </button>
+</template>