fix: preserve SSH profile on sync round-trip and save fallback config

[datlechin]

Summary

• SyncRecordMapper was missing sshProfileId in both toCKRecord and toConnection — on iCloud sync round-trip, the profile UUID was dropped and the connection reverted to inline SSH config showing "SSH : @"
• ConnectionFormView.saveConnection() stored empty inline sshConfig (host="", username="") when an SSH profile was selected, because the inline fields were never filled. Now copies profile data into the fallback config
• reloadProfiles() could clear sshProfileId when SSHProfileStorage.loadProfiles() returned empty due to a decode failure. Now checks lastLoadFailed before clearing

Test plan

• Create SSH profile, assign to connection, save
• Quit app → relaunch → verify profile still selected, subtitle shows correct SSH info
• Connect → disconnect → back to welcome → verify profile preserved
• Edit connection → verify profile picker shows correct selection
• Delete SSH profile → verify connection falls back to inline config with correct data (not empty)
• With iCloud Sync enabled: verify profile survives sync cycle