feat: add MCP server with resources, tools, auth, and Traefik routing

- Add backend/app/mcp_server.py with FastMCP server (hms-cms)
- Resources: design-rules, page-structure, sync-status
- Tools: trigger_sync, get_sync_log, set_rentman_token, read_file,
  write_file, create_page, deploy, git_commit, git_status
- Bearer token auth via MCP_AUTH_TOKEN env var
- Mount MCP at /mcp with streamable HTTP transport
- Integrate session manager in FastAPI lifespan
- Add Traefik labels for external /mcp route on hms.media-on.de
- Add git, docker.io, curl to backend Dockerfile
- Mount repo root + docker socket in backend container
- Add mcp>=1.0.0 to requirements.txt

frontend-nuxt-old/components/EmptyState.vue

@@ -0,0 +1,13 @@
+<template>
+  <div class="text-center py-16 px-4" role="status">
+    <div class="text-6xl mb-4" aria-hidden="true">{{ icon }}</div>
+    <h3 class="text-xl font-semibold mb-2" style="color: var(--text)">{{ title }}</h3>
+    <p class="max-w-md mx-auto mb-6" style="color: var(--secondary)">{{ message }}</p>
+    <button v-if="actionLabel" @click="$emit('action')" class="hms-btn hms-btn-primary">{{ actionLabel }}</button>
+  </div>
+</template>
+
+<script setup lang="ts">
+withDefaults(defineProps<{ icon?: string; title: string; message: string; actionLabel?: string }>(), { icon: '🔍' })
+defineEmits<{ action: [] }>()
+</script>