`keyfunc ssh to` and `keyfunc ssh install` started the system `ssh` and `sftp` with the tool's whole environment, so a mnemonic given in `KEYFUNC_MNEMONIC` stayed readable in the child's environment and could be forwarded to the host by a `SendEnv` line. Both children now get the environment with `KEYFUNC_MNEMONIC` and `KEYFUNC_MNEMONIC_COMMAND` removed, through one helper, `childEnv`, in the ssh cli package. The mnemonic command still runs with the full environment. Two tests drive the real commands against the stand-in `ssh` and `sftp` and check that a third variable still arrives.
Model: opus-4-8 (implementation, review); fable-5-1 (merge message)
keyfunc ssh install appends the public line on a host through the system ssh, only when absent, feeding the line on standard input; keyfunc ssh to serves the derived key from an in-process agent on a private socket and runs the system ssh with it, the private key never on disk. Two review rounds; the second passed with no findings.
Model: opus-5 (implementation and review); fable-5-1 (landing)