feat: update documentation and component demos for backend layered architecture

- Add new LanguageScopeDemo component for backend languages overview
- Refactor and simplify existing demo components (ControllerLayerDemo, DtoFlowDemo, DependencyDirectionDemo)
- Update .gitignore to exclude .claude/skills directory
- Modify backend-related sections in documentation from "后端与全栈" to "后端开发"
- Add new backend layered architecture demo components (CleanArchitectureDemo, DependencyDirectionDemo)
- Improve documentation structure and content for stage-3 core skills
- Fix component initialization timing in CompileVsInterpretDemo and RateLimiterDemo
- Add design style prompt reference in frontend documentation

docs/.vitepress/theme/components/appendix/rate-limiting/RateLimiterDemo.vue

@@ -65,7 +65,7 @@
 </template>
 
 <script setup>
-import { ref, computed } from 'vue'
+import { ref, computed, onMounted, onUnmounted } from 'vue'
 
 const algo = ref('token')
 const totalSent = ref(0)
@@ -105,9 +105,19 @@ function reset() {
   recentRequests.value = []
   windowRequests.value = []
   if (tokenInterval) clearInterval(tokenInterval)
-  startTokenRefill()
+  // 只在令牌桶模式下启动补充
+  if (algo.value === 'token') startTokenRefill()
 }
 
+onMounted(() => {
+  // 组件挂载后启动令牌补充，避免模块加载时启动定时器导致 build 卡住
+  startTokenRefill()
+})
+
+onUnmounted(() => {
+  if (tokenInterval) clearInterval(tokenInterval)
+})
+
 function checkLimit() {
   if (algo.value === 'token') {
     if (tokens.value > 0) { tokens.value--; return true }
@@ -156,8 +166,6 @@ async function sendBurst() {
     await new Promise(r => setTimeout(r, 100))
   }
 }
-
-startTokenRefill()
 </script>
 
 <style scoped>