fix: 清理 unused-vars 回归(32→0) + 修复 go:embed 编译阻塞

1. ESLint unused-vars 从 32 清零（回归修复）
   - 删除 14 个文件中未使用的 import（lucide 图标/shadcn 组件/JsonData 类型）
   - 移除未使用的变量/参数（categoryLabels/updateEntry/onSaved 等）
   - 涉及: AppRelease/PipelineEditor/KubernetesNodes/AlertCenter/SilenceRulesPanel 等

2. 修复 go:embed all:static 编译阻塞
   - 新增 backend/static/.gitkeep 占位文件
   - 全新 clone 后 go build ./... 可直接通过（不再依赖先 npm run build）

3. 安装缺失的 npm 依赖
   - react-markdown/remark-gfm（AgentMarkdown 组件）
   - @codemirror/lang-python/@codemirror/legacy-modes（ScriptCodeEditor 组件）

验证: go build✅ | tsc -b✅ | npm build✅(21s) | ESLint any=41 unused=0 | 17/17 集成测试✅

frontend/src/components/kubernetes/DeploymentEditService.tsx

@@ -74,7 +74,7 @@ interface _SvcPortForm {
 
 const toArray = ( v: any) => (Array.isArray(v) ? v : (v?.list || v?.items || v?.data || []));
 
-export function DeploymentEditService({ clusterCode, namespace, deploymentName, manifest, onSaved, onCancel }: Props) {
+export function DeploymentEditService({ clusterCode, namespace, deploymentName, manifest, onCancel }: Props) {
   const { toast } = useToast();
   const confirm = useConfirm();
   const [loading, setLoading] = useState(true);

frontend/src/components/kubernetes/DeploymentEditStorage.tsx

@@ -96,9 +96,6 @@ export function DeploymentEditStorage({ clusterCode, namespace, deploymentName,
 
   const defaultContainer = containers.find((c) => c !== '(unnamed)') || containers[0] || '';
 
-  const updateEntry = (i: number, patch: Partial<VolumeEntry>) =>
-    setEntries((prev) => prev.map((e, idx) => (idx === i ? { ...e, ...patch } : e)));
-
   const updateVolume = (i: number, patch: Partial<VolumeForm>) =>
     setEntries((prev) => prev.map((e, idx) => (idx === i ? { ...e, volume: { ...e.volume, ...patch } } : e)));
 

frontend/src/components/kubernetes/DeploymentWorkload.tsx

@@ -14,7 +14,6 @@ import {
   RotateCw,
   Trash2,
   RefreshCw,
-  Loader2,
   XCircle,
   CheckCircle,
   AlertTriangle,

frontend/src/components/kubernetes/KubernetesNodes.tsx

@@ -1,5 +1,4 @@
 import { useState, useEffect, useCallback } from 'react';
-import { Card, CardContent } from '@/components/ui/card';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
 import { Badge } from '@/components/ui/badge';

frontend/src/components/kubernetes/NodeDetailPage.tsx

@@ -10,7 +10,6 @@ import {
 import {
   
   RefreshCw,
-  Loader2,
   Server,
   Activity,
   ArrowLeft,