fix(darwin): remove unused self from macmini specialArgs; fix developerDirs sops timing
- Drop `specialArgs = { inherit self; }` from darwinConfigurations.macmini —
self was never consumed and caused a builtins.derivation context warning
- Add setupSecrets to developerDirs dag dependencies so sops secrets are
available before repo cloning runs
- Fall back to direct sops decryption with age key when sops-nix hasn't yet
written the decrypted token file (Darwin launchd timing issue)
- Export GIT_SSH_COMMAND to ensure ssh is on PATH during activation
- Remove launchd user agents for Tailscale and AltServer launchers