Merge branch 'master' into worktree/dsh-arg-parser

Integrate the Commander adapter with master's headless rework (dsh -p now boots
through AppCLIEntry — the same cordis.yml composition as dsh web, web-observable
while it runs — via toFetchHandler(ctx.apiProxy)).

- headless.ts: keep master's AppCLIEntry-based body but take the adapter's
  pre-parsed `task` (drop the re-added parseArgs). Old startHost path and the
  now-deleted packages/host/runtime dependency are gone.
- remove the stale packages/host/runtime dir left on disk by master's deletion
  (mirrors the earlier packages/ui/acp cleanup).

apps/cli/package.json

@@ -37,7 +37,6 @@
     "@deepseek-ai/dsh-fs-local": "workspace:^",
     "@deepseek-ai/dsh-fs-policy": "workspace:^",
     "@deepseek-ai/dsh-host-apiproxy": "workspace:^",
-    "@deepseek-ai/dsh-host-runtime": "workspace:^",
     "@deepseek-ai/dsh-host-webserver": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
     "@deepseek-ai/dsh-llm-deepseek": "workspace:^",