Fix Windows unreachable-network error for PACE Ethernet

[SebRoLENS]

Root cause

The cross-platform Python client assigned 192.168.10.1/24 to the dedicated adapter but retried immediately without reproducing the remaining network setup used by the validated Windows controller. On a PC with several active adapters this can leave Windows without a usable route to 192.168.10.2, producing [WinError 10051] before any SCPI command is sent.

Fix

• wait until Windows reports 192.168.10.1 as Preferred;
• ensure an explicit temporary on-link route for 192.168.10.0/24 on the selected adapter;
• bind the retrying TCP socket to 192.168.10.1;
• enable TCP_NODELAY, matching the legacy implementation;
• track and remove only the temporary route/address created by the app;
• reject a conflicting 192.168.10.0/24 on another physical adapter.

Validation

• added a regression test for adapter index 3 with 169.254.233.163/16 and no gateway;
• added a transport test asserting source binding to 192.168.10.1 and TCP_NODELAY;
• 19 passed in the cross-platform pytest suite;
• all 7 repository consistency tests pass;
• Python sources compile successfully;
• git diff --check passes.

The frozen PowerShell implementation remains unchanged.