Fix empty Cisco IOSv CLI output and harden Windows stop/start.

Drain leftover prompts before Netmiko send_command, and make stop/start tolerate orphan workers and locked log files.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_ne_netmiko_show.py

@@ -0,0 +1,49 @@
+"""Tests for Netmiko show helpers (IOSv leftover-prompt drain / retry)."""
+
+from __future__ import annotations
+
+import unittest
+from unittest.mock import MagicMock, call, patch
+
+from netx_api.ne_netmiko import drain_read_channel, send_show_command
+
+
+class DrainReadChannelTests(unittest.TestCase):
+    def test_drains_until_idle(self) -> None:
+        conn = MagicMock()
+        conn.read_channel.side_effect = ["R2#\n", "", "", "", ""]
+        out = drain_read_channel(conn, idle_reads=3, pause_sec=0.0)
+        self.assertEqual(out, "R2#\n")
+        self.assertGreaterEqual(conn.read_channel.call_count, 4)
+
+    def test_clear_buffer_when_no_read_channel(self) -> None:
+        conn = MagicMock(spec=["clear_buffer"])
+        self.assertEqual(drain_read_channel(conn), "")
+        conn.clear_buffer.assert_called_once()
+
+
+class SendShowCommandTests(unittest.TestCase):
+    @patch("netx_api.ne_netmiko.drain_read_channel")
+    def test_returns_first_nonempty_send_command(self, drain: MagicMock) -> None:
+        conn = MagicMock()
+        conn.send_command.return_value = "*12:00:00 UTC"
+        out = send_show_command(conn, "show clock", read_timeout=30)
+        self.assertEqual(out, "*12:00:00 UTC")
+        conn.send_command.assert_called_once()
+        conn.send_command_timing.assert_not_called()
+        drain.assert_called()
+
+    @patch("netx_api.ne_netmiko.drain_read_channel")
+    def test_retries_then_falls_back_to_timing_when_empty(self, drain: MagicMock) -> None:
+        conn = MagicMock()
+        conn.send_command.return_value = ""
+        conn.send_command_timing.return_value = "Cisco IOS Software"
+        out = send_show_command(conn, "show version", read_timeout=30)
+        self.assertEqual(out, "Cisco IOS Software")
+        self.assertEqual(conn.send_command.call_count, 2)
+        conn.send_command_timing.assert_called_once_with("show version", read_timeout=30)
+        self.assertGreaterEqual(drain.call_count, 2)
+
+
+if __name__ == "__main__":
+    unittest.main()