stdout Resource Leak

[claymore666]

LOCATION: ceti/whaletag.py:51-57

CURRENT CODE:
sys.stdout = open(os.devnull, "w")
lanhosts = asyncio.run(coro)
sys.stdout = sys.stdout

PROBLEM:
- stdout is redirected to /dev/null to suppress findssh output
- If asyncio.run() raises an exception, line 3 never executes
- stdout stays redirected to /dev/null forever
- All subsequent output disappears

IMPACT:
- All error messages after the failure are invisible
- Debugging becomes impossible
- Requires program restart to see output again

[InterstellarIntruder]

Planning to look at this next.

[InterstellarIntruder]

Put up a proposed fix in #45.

Summary:

• Replaced manual sys.stdout swapping in find_ssh_servers() with open(os.devnull) + contextlib.redirect_stdout(...)
• This guarantees stdout restoration even when asyncio.run() raises
• Added 3 tests proving stdout is restored on success and on failures at both scan call sites

Would appreciate review from anyone working on whaletag reliability flows.