feat: 用户端显示金山文档在线状态

- 新增 /api/kdocs/status 接口（用户端简化版）
- 工具栏显示"表格上传: ✅ 就绪"或"⚠️ 离线"
- 页面加载时获取状态，每60秒自动刷新
- 系统未启用时不显示

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

routes/api_user.py

@@ -348,3 +348,37 @@ def get_run_stats():
             "today_attachments": stats.get("total_attachments", 0),
         }
     )
+
+
+@api_user_bp.route("/api/kdocs/status", methods=["GET"])
+@login_required
+def get_kdocs_status_for_user():
+    """获取金山文档在线状态（用户端简化版）"""
+    try:
+        # 检查系统是否启用了金山文档功能
+        cfg = database.get_system_config() or {}
+        kdocs_enabled = int(cfg.get("kdocs_enabled") or 0)
+
+        if not kdocs_enabled:
+            return jsonify({"enabled": False, "online": False, "message": "未启用"})
+
+        # 获取金山文档状态
+        from services.kdocs_uploader import get_kdocs_uploader
+
+        kdocs = get_kdocs_uploader()
+        status = kdocs.get_status()
+
+        login_required_flag = status.get("login_required", False)
+        last_login_ok = status.get("last_login_ok")
+
+        # 判断是否在线
+        is_online = not login_required_flag and last_login_ok is True
+
+        return jsonify({
+            "enabled": True,
+            "online": is_online,
+            "message": "就绪" if is_online else "离线"
+        })
+    except Exception as e:
+        logger.error(f"获取金山文档状态失败: {e}")
+        return jsonify({"enabled": False, "online": False, "message": "获取失败"})