Wires the existing SSHConnectionCard and SSHSessionsCard into the
settings UI so the SSH executor flow has a home:
- /settings/executors/new/ssh renders SSHCreatePage (just the connection
card; Save POSTs a new executor and routes to the edit page).
- /settings/executors/ssh/[executorId] loads the executor and renders
the connection card pre-filled + the sessions card.
- Adds the SSH entry to the executors landing-page tile grid.
- Adds createExecutor / fetchExecutor / updateExecutor helpers to
settings-api so the new pages can talk to /api/v1/executors directly.
Profile management for SSH executors still flows through the existing
profile pages; this commit only adds the executor-level chrome the
SSHSettingsPage e2e tests expect.
José Almeida