fix(cli): bound telemetry shutdown on signals

Refs #1356

apps/cli/README.md

@@ -23,6 +23,8 @@ The TUI surface:
 
 The Web and headless surfaces boot `base.cordis.yml` plus `web.cordis.yml`, then apply `$DSH_HOME/config.yaml`; an explicit `--config <path>` replaces that personal overlay. Both surfaces otherwise share the same composition: both tell the coding agent its resolved model and session working directory, treat the invoking directory as the default project and Workspace root, create named Workspaces beneath that root unless `--workspace-root <path>` overrides it, load applicable `AGENTS.md`/`CLAUDE.md` instructions into each agent-loop request prefix with a 65,536-byte render budget, opt into first-message model titles, use the same bounded transient model-request retry policy as the TUI, and mount a disposable in-memory SQLite content-index service. Web additionally names the DeepSeek Harness Web GUI as the interaction surface, this checkout as its own source location, and the process's canonical local URL and mode in both the prompt and managed `$DSH_WEB_URL`/`$DSH_WEB_MODE`; references such as “this page” therefore identify the GUI without claiming access to implicit DOM, route, or screenshot state. In production mode the host reads rebuilt frontend dist and client bundles on the next request, so refreshing the existing URL updates that GUI without replacing its process. `dsh web --dev` mounts the client-plugin HMR receiver, but no-refresh updates additionally require `pnpm run dev:web` in the same checkout to watch and rebuild plugin bundles; shell and ordinary package changes still require a rebuild and page refresh. Bare `apps/web` Vite serving fails before listening because it cannot inject `window.__DSH_BOOT__`. The index service is ACTIVE at boot, while its `node:sqlite` module and database handle open only on the first content search. This keeps Node 22 startup output free of SQLite's experimental warning before search is used; the first actual search may still emit the runtime warning. Each service instance owns its database, so parallel invocations neither share unsupported SQLite state nor leave derived index files behind, and the first search lazily reconciles live and persisted logs. Headless differs only in listening on an OS-assigned port (parallel `dsh -p` runs never collide; the stderr-printed URL opens the live session in a browser). Both need the frontend dist and client bundles built (`pnpm run build && pnpm run build:web`).
 
+Web and headless process shutdown gives the plugin tree up to five seconds to dispose. The first `SIGINT`/`SIGTERM` starts that graceful drain; a second signal forces immediate exit. If headless normal completion is already stuck in disposal, the first `Ctrl+C` is the escalation and exits immediately instead of being swallowed.
+
 The shared composition defaults new TUI, Web, and headless sessions to the `workspace-write` permission preset (`workspace-write` file mode plus `ask` approval policy). Sandbox-enforced bash and filesystem mutations may write only under the session workspace and platform temporary roots; reads, network access, and process visibility are not confined. The browser answers one-shot approval requests and exposes the Access picker; the TUI exposes `/permission`, but has no approval-request answerer, so an automatic wider retry there fails closed until the user deliberately changes the session preset. `DSH_PERMISSION_MODE` changes the process fallback, while a stored General-settings Permission value applies to later sessions without changing an open one.
 
 All three surfaces consume `$DSH_HOME/config.yaml`; the TUI and Web apply valid edits live, while one-shot headless runs read it at startup. The shipped trees include an empty `repository-plugins` row, so a standalone user can add prepared GitHub Plugins without an SDK project or install command: