feat: Establish WebUI build process, update frontend assets, and add CI workflow.

scripts/build-webui.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+# WebUI 构建脚本
+# 用法: ./scripts/build-webui.sh
+
+set -e
+
+echo "🔨 Building WebUI..."
+
+cd "$(dirname "$0")/../webui"
+
+# 检查 node_modules
+if [ ! -d "node_modules" ]; then
+    echo "📦 Installing dependencies..."
+    npm install
+fi
+
+# 构建
+echo "🏗️  Running build..."
+npm run build
+
+echo "✅ WebUI built successfully!"
+echo "📁 Output: static/admin/"