Master removed the TUI package, the `meta` and `upgrade` subcommands, and
`--config-replace`, and made raw `dsh` require a `--config` overlay. Resolved
onto that shape:
- Dropped this branch's TUI edits with the surface itself, including
`tui.cordis.yml`, `runTui`, and the TUI keyless PTY smoke.
- Dropped the `--config-replace` plumbing rather than reintroducing a flag
master deliberately removed. The gap this branch fixed remains: `dsh -p`
still could not name its composition, so it keeps `--config`.
- Kept this branch's deletion of the personal `$DSH_HOME/config.yaml` layer,
which master still carried, and provided the environment snapshot in the new
raw `runConfig` surface alongside web and headless.
- Ported the headless shutdown PTY test off the personal overlay onto a named
`--config` file, which is what proves that flag now exists on `-p`.