Initial commit: OpenVPN Manager v1.0

OpenVPN Web management console with multi-instance support, client cert
issuance, traffic/connection auditing, certificate expiry reminders,
auto backup/restore.

Stack:
- Backend: Go 1.21+ (Gin + JWT)
- Frontend: Vue 3 + Element Plus + ECharts + Vite
- Storage: JSON file (db.json) + filesystem (pki/, instances/, clients/, backups/)

Features:
- Multi-instance OpenVPN management (independent port/proto/subnet/PKI)
- One-click client certificate issuance with .ovpn (embedded certs)
- Certificate expiry reminders (30-day threshold)
- Connection log parsing (status-version 3)
- Auto backup/restore (tar.gz)
- Audit log for all write operations
- JWT auth (12h TTL)
- One-line install.sh for Ubuntu/Debian/RHEL/Fedora

frontend/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "openvpn-manager-frontend",
+  "version": "1.0.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview --port 4173"
+  },
+  "dependencies": {
+    "@element-plus/icons-vue": "^2.3.1",
+    "@vitejs/plugin-vue": "^5.1.4",
+    "axios": "^1.7.7",
+    "echarts": "^5.5.1",
+    "element-plus": "^2.8.4",
+    "pinia": "^2.2.4",
+    "vite": "^5.4.8",
+    "vue": "^3.5.10",
+    "vue-echarts": "^7.0.3",
+    "vue-router": "^4.4.5"
+  }
+}