feat: edc-web 设备日志管理页 + 在线状态实时刷新

- 新增 /device-logs 设备事件日志管理页 (admin 权限)
  - 支持按设备序列号/事件类型筛选查询
  - 支持 admin 按条件删除日志
  - 不同事件类型彩色标识 (在线=绿, 离线=红, 通信不良=橙)
- 新增 /api/devices/<id>/status 设备状态 API
- 设备列表页：每 5s 异步刷新所有设备在线状态
- 测试操作页：顶部显示设备状态，每 5s 异步刷新
- dnt_info state 支持三态显示 (在线/离线/通信不良)
- 导航栏增加「设备日志」入口 (admin only)

edc-web/app/routes/device_logs.py

@@ -0,0 +1,58 @@
+"""设备事件日志 API"""
+
+from flask import Blueprint, jsonify, render_template, request
+from flask_login import login_required, current_user
+from app.models import get_device_logs, delete_device_logs, insert_log
+
+bp = Blueprint("device_logs", __name__)
+
+
+@bp.route("/device-logs")
+@login_required
+def index():
+    """设备日志页面"""
+    return render_template("device_logs.html")
+
+
+@bp.route("/api/device-logs")
+@login_required
+def api_device_logs():
+    """查询设备事件日志"""
+    page = request.args.get("page", 1, type=int)
+    per_page = request.args.get("per_page", 30, type=int)
+    serial = request.args.get("serial", "", type=str)
+    event_type = request.args.get("event_type", "", type=str)
+
+    records, total = get_device_logs(
+        page=page, per_page=per_page,
+        serial=serial, event_type=event_type,
+    )
+    pages = max(1, (total + per_page - 1) // per_page)
+    return jsonify({"records": records, "total": total, "pages": pages})
+
+
+@bp.route("/api/device-logs/delete", methods=["POST"])
+@login_required
+def api_device_logs_delete():
+    """删除设备日志（admin 权限）"""
+    if current_user.role != "admin":
+        return jsonify({"ok": False, "error": "无权限"}), 403
+
+    data = request.get_json()
+    serial = data.get("serial", "")
+    event_type = data.get("event_type", "")
+    date_from = data.get("date_from", "")
+    date_to = data.get("date_to", "")
+
+    deleted = delete_device_logs(
+        serial=serial, event_type=event_type,
+        date_from=date_from, date_to=date_to,
+    )
+    insert_log(
+        current_user.id, current_user.username, "delete",
+        target="device_log",
+        detail=f"删除 {deleted} 条设备日志 serial={serial} type={event_type}",
+        result="ok",
+        ip=request.remote_addr or "",
+    )
+    return jsonify({"ok": True, "deleted": deleted})