feat: SSHClient v1.0.0 - PyQt5 + paramiko 跨平台 SSH 客户端

功能:
- 多主机管理 (增删改查, 密码/私钥双认证, 导入导出)
- 远程终端 (命令执行 + 常用命令快捷栏 + 超时控制)
- SFTP 文件浏览 (上传/下载带进度, 新建/删除/重命名)
- 实时监控 (CPU/内存/磁盘/网络, 1-10秒可调刷新)
- AI Agent (OpenAI 兼容 API, 5 工具自动调用: 命令/指标/列文件/读文件/上传)

技术栈: PyQt5 + paramiko + psutil + requests + PyInstaller
打包: build_windows.bat / build.sh 一键产出 ~57MB 单文件 exe
测试: core 6/6 + UI 3/3 + E2E 6/6 全部通过

capture_screens.py

@@ -0,0 +1,65 @@
+"""
+UI 渲染截图：用 QWidget.grab() 把主窗口、各 Tab 渲染成 PNG。
+不开真实显示器，offscreen 平台即可。
+"""
+import os
+import sys
+
+os.environ["QT_QPA_PLATFORM"] = "offscreen"
+sys.path.insert(0, os.path.dirname(__file__))
+
+from PyQt5.QtWidgets import QApplication
+from PyQt5.QtCore import QTimer, Qt
+from PyQt5.QtGui import QPixmap
+
+from ui.main_window import MainWindow
+
+
+def main():
+    out_dir = os.path.join(os.path.dirname(__file__), "screenshots")
+    os.makedirs(out_dir, exist_ok=True)
+    app = QApplication(sys.argv)
+    w = MainWindow()
+    w.resize(1280, 800)
+    w.show()
+    # 等一帧
+    QTimer.singleShot(500, lambda: grab_and_quit(w, app, out_dir))
+    app.exec_()
+
+
+def grab_and_quit(w, app, out_dir):
+    # 主窗口
+    pix = w.grab()
+    p = os.path.join(out_dir, "main_window.png")
+    pix.save(p, "PNG")
+    print(f"[1/4] 主窗口: {p} ({pix.width()}x{pix.height()})")
+
+    # 各 Tab
+    for idx, name in enumerate(["terminal", "files", "monitor", "ai"]):
+        w.tabs.setCurrentIndex(idx)
+        app.processEvents()
+        pix = w.grab()
+        p = os.path.join(out_dir, f"tab_{idx}_{name}.png")
+        pix.save(p, "PNG")
+        print(f"[{idx+2}/5] Tab '{name}': {p}")
+
+    # 主机对话框
+    from ui.host_dialog import HostDialog
+    dlg = HostDialog(w, current={"name": "示例", "host": "192.168.1.1", "port": 22,
+                                  "username": "root", "password": "", "key_path": ""})
+    dlg.show()
+    app.processEvents()
+    QTimer.singleShot(200, lambda: finalize(dlg, app, out_dir))
+
+
+def finalize(dlg, app, out_dir):
+    pix = dlg.grab()
+    p = os.path.join(out_dir, "host_dialog.png")
+    pix.save(p, "PNG")
+    print(f"[5/5] HostDialog: {p}")
+    dlg.close()
+    app.quit()
+
+
+if __name__ == "__main__":
+    main()