Documents why `ansible myhost -m ping` fails with Permission denied
while `ssh myhost` works — SSH Host blocks match on literal pattern,
not on resolved HostName, so `ansible_host: <IP>` bypasses the alias
and the declared IdentityFile never gets applied. Covers the portable
fix (ansible_ssh_private_key_file in host_vars), the symlink sidebar
for standardizing key names across control nodes, alternatives, and
a diagnosis checklist.
Also catches index.md up with the ansible-check-mode-false-positives
article that was already published but missing from the nav.
