Fix memory corruption and support WinPE

[eransha-salvador]

Summary

• Fix format-string mismatch in load_user_profile (%s %S %d with two args) that corrupts memory and crashes sshd-session post-auth when LoadUserProfileW fails.
• Delay-load user32.dll in sshd-auth so it survives restricted window stations (e.g. WinPE) where user32's DllMain fails with STATUS_DLL_INIT_FAILED. The only transitive user32 references (ShowWindow / GetWindowPlacement via ConRestoreViewRect_NoPtyHack) are unreachable in sshd-auth, so the DLL is never loaded in practice.

Stacked on #840 — please merge that first. Until #840 lands, this PR's diff view also shows its commit; after #840 merges, this PR will rebase down to just the two commits above.

Fixes PowerShell/Win32-OpenSSH#2435

Test plan

• Boot WinPE, run sshd, and verify the daemon stays up across an authentication attempt (no sshd-session / sshd-auth crash).
• On regular Windows, confirm no behavior change for normal profile-enabled logons.

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[tgauth]

If it's only a transitive reference, does removing the dependency on the DLL from sshd-auth, instead of delay loading, work?

[eransha-salvador]

@tgauth it won't work.
The use of the user32 lib done in a static library (posix_compat) - since it is static the link is done only in the containing app project (ssh_auth).
If we remove the user32.lib entirely (including from the default additional dependencies) - the link stage will fail to find ShowWindow and GetWindowPlacement.
I used dumpbin /dependents bin\x64\Release\sshd-auth.exe to verify that the user32 is delayed init when adding it explicitly as I did in this pr.
If I will remove it entirely (including from the default additional dependencies) - the link fails.
If I remove it explicitly but keep it in the default additional dependencies - the link pass but user32 will no longer be delayed - which means it will try to load it statically, which in the PE scenario on the launched user fail (due to the original issue that the user it is being launched for has no permission for the resource).

If it's only a transitive reference, does removing the dependency on the DLL from sshd-auth, instead of delay loading, work?

[tgauth]

/azp run

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