Why do I need to run `ssh-add` in my Powershell profile?
It's because your rsa key is not the default name ( id_rsa ) so you either need to use ssh-add (which adds it to a running service that remembers the key decrypted with your passphrase) or just add an entry into your ~\.shh\config
~\.ssh\config (create or edit):
Host github.com HostName github.com User git IdentityFile ~/.ssh/github_rsaOr, if github is the only thing you use ssh keys for, just rename the key to id_rsa and then git (well ssh.exe) will find it for you automatically AND poshgit will ssh-add it for you (to handle passphrases).