Merge branch 'master' into claude/unified-environment-credentials-c8841a

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`.

docs/user/guide/config.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/user/guide/config.md
-config.md: b1cf3a57b2fd16d4139f1a11a6cd85e54bb957b5
-config.zh.md: dad03d8232851678cfb6dc690f0bbd3f02380fc8
+config.md: 580c62be717efcca3ff5cd01d144722fba703051
+config.zh.md: 7621c846d706e661c118786e34b55cdf23bf730e