Support SSH deep links for adding connections and starting threads in remote folders

What variant of Codex are you using?

App

What feature would you like to see?

Codex currently supports:

codex://settings/connections/ssh/add?name=devbox

but name here means an existing Host devbox entry in ~/.ssh/config. It would be great to support SSH config aliases, Codex-saved connections and manual configurations.

First, expand the SSH add route to match the Add SSH connection UI:

codex://settings/connections/ssh/add?
  displayName=Devbox
  &hostname=user%40host.com
  &sshPort=22
  &authMode=identity
  &identityFilePath=%2FUsers%2Fme%2F.ssh%2Fid_ed25519

Suggested params:

sshConfigName=       existing Host alias from ~/.ssh/config
displayName=         Codex connection display name to save
hostname=            host.com or user@host.com
sshPort=             optional SSH port
authMode=            none | identity
identityFilePath=    used when authMode=identity

name= could remain as a backward-compatible alias for sshConfigName=, but the clearer param should distinguish it from Codex’s saved display name.

Second, add a new-thread route for SSH remote folders. This should reuse an existing saved Codex connection when possible, or create one first if full connection details are provided.

Example: create or reuse a connection, then start a new thread in a remote folder:

codex://threads/new?
  remote=ssh
  &displayName=Devbox
  &hostname=user%40host.com
  &sshPort=22
  &authMode=identity
  &identityFilePath=%2FUsers%2Fme%2F.ssh%2Fid_ed25519
  &remoteFolder=%2Fhome%2Fme%2Frepo
  &prompt=Fix%20the%20failing%20tests

Example: open by existing saved Codex connection display name:

codex://threads/new?
  remote=ssh
  &savedConnectionDisplayName=Devbox
  &remoteFolder=%2Fhome%2Fme%2Frepo
  &prompt=Fix%20the%20failing%20tests

Example: open via an existing SSH config alias:

codex://threads/new?
  remote=ssh
  &sshConfigName=devbox
  &remoteFolder=%2Fhome%2Fme%2Frepo
  &prompt=Fix%20the%20failing%20tests

Expected behavior:

• savedConnectionDisplayName looks up an existing Codex-saved SSH connection.
• displayName is the name to save when creating a new Codex-managed SSH connection.
• sshConfigName refers only to an existing Host entry in ~/.ssh/config.
• If a matching saved connection already exists, reuse it.
• If no saved connection exists but full connection params are provided, prefill or create the SSH connection after user confirmation, then continue to the thread.
• Use remoteFolder for the remote filesystem path, leaving existing local path behavior unchanged.
• Require confirmation before saving or connecting to a new SSH host.

Additional information

VS Code supports something similar (but simpler): https://github.com/microsoft/vscode-remote-release/issues/4779#issuecomment-1220475865