refactor(cli): bail early in the arg adapter instead of returning errors as data

Address review and cut ceremony: the adapter no longer models help/version/
errors as DshInvocation members. Commander owns those under exitOverride — it
prints usage or the diagnostic and one try/catch in parseDshArgs turns the
thrown CommanderError into process.exit with the intended code. bin.ts drops its
help/version/error cases; the union is the three real modes.

Domain checks bail via command.error(print + exit 1): --prompt rejects an empty
task or a stray config/--resume, empty --resume= fails loud, and --host/--port
are validated. A repeated --resume or a flag captured as a value is Commander's
standard behavior, left alone (a bad id fails loud downstream). dsh --help
discloses web via addHelpText. Net: args.ts 185 -> 112 lines.

Also fixes review nits: built-bin e2e resolves on `close`; the /resume handoff
uses `dsh --resume=<id> -- <config>` so a config named `web` stays a positional;
and stale prose (cordis.yml comment, app-boot module doc + duplicate JSDoc,
ui/README, two feature notes, an agent-loop test name) tracks the shipped state.
Removes tui-demo's now-dead plugin-include dep and vendor/loader + app-boot
tsconfig references.

packages/ui/app-boot/src/index.ts

@@ -1,5 +1,5 @@
 /**
- * Shared boot glue for the app bins (`dsh-tui-demo`, `dsh-cli-demo`, `dsh-acp-demo`): load the gitignored
+ * Shared boot glue for the app bins (`dsh`, `dsh-cli-demo`, `dsh-acp-demo`): load the gitignored
  * `.env`, install the fail-loud Loader guards, resolve the config path (snapshot-aware), load the
  * optional personal overlay patches from the Harness home (`~/.dsh`), and drive the cordis Loader
  * against a leaf `cordis.yml` until the whole tree has settled.
@@ -156,7 +156,6 @@ export function assertEntriesLoaded(ctx: Context, binName: string): void {
   }
 }
 
-/**
 /**
  * Context key a bin sets through {@link boot}'s `prepare` hook to hand a resume
  * session id to the booted config: `ctx.provide(RESUME_SESSION_ID_KEY, id)`