Add topology NE create/connect flows and trim connect-test logs.

Bring full managed-NE create onto the canvas (keep placeholders), add single/multi connect test and multi discover links, split topology/managedNe dialogs into modules, and shorten redundant connectivity failure details.

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

tests/test_ne_connect_detail.py

@@ -0,0 +1,61 @@
+"""Connect-failure detail formatting should stay short and non-redundant."""
+
+from __future__ import annotations
+
+from netx_api.ne_connect import (
+    _exc_headline,
+    _format_failure_detail,
+    _is_network_reachability_fail,
+    _root_cause_headline,
+)
+
+
+def test_exc_headline_uses_first_line_only() -> None:
+    exc = Exception("TCP connection to device failed.\n\nCommon causes of this problem are:\n1. wrong IP")
+    assert _exc_headline(exc) == "Exception: TCP connection to device failed."
+    assert "Common causes" not in _exc_headline(exc)
+
+
+def test_root_cause_headline() -> None:
+    try:
+        try:
+            raise TimeoutError("[WinError 10060] timed out")
+        except TimeoutError as inner:
+            raise RuntimeError("TCP connection to device failed.") from inner
+    except RuntimeError as outer:
+        root = _root_cause_headline(outer)
+        assert root is not None
+        assert "TimeoutError" in root
+        assert "10060" in root
+
+
+def test_format_failure_detail_omits_stack_for_timeout() -> None:
+    creds = {
+        "ip_address": "192.168.0.127",
+        "port": 22,
+        "protocol": "ssh",
+        "device_type": "huawei",
+        "vendor": "Huawei",
+        "username": "huawei",
+        "hop_enabled": False,
+    }
+    try:
+        try:
+            raise TimeoutError("[WinError 10060] timed out")
+        except TimeoutError as inner:
+            raise RuntimeError(
+                "TCP connection to device failed.\n\nCommon causes of this problem are:\n1. firewall"
+            ) from inner
+    except RuntimeError as outer:
+        assert _is_network_reachability_fail(outer)
+        detail = _format_failure_detail(creds, outer)
+
+    assert "target=192.168.0.127:22/ssh" in detail
+    assert "hop=disabled (direct)" in detail
+    assert "result=fail" in detail
+    assert "error=RuntimeError: TCP connection to device failed." in detail
+    assert "cause=TimeoutError:" in detail
+    assert "Common causes" not in detail
+    assert "Traceback" not in detail
+    assert "stack:" not in detail
+    assert "File \"" not in detail