herdr agent panel keeps a stale nikcli row after nikcli quits

[SandroHub013]

Description

Quitting nikcli leaves a stale nikcli row in herdr's agent panel. It only disappears when you type exit in the pane's shell, which kills the pane itself.

Herdr clears an agent automatically only for the agents it recognizes by process. nikcli is reported, not detected, so herdr keeps the row until someone calls pane.release_agent. Nothing does:

• HerdrPlugin.dispose() calls HerdrBridge.stop(), and stop() only resets local runtime state — no release.
• releasePane() exists but is only reachable from the agent-facing herdr tool and releaseSession().

So claude, agy, pi and the rest drop out of the panel when they exit, and nikcli doesn't.

Note process.on("exit") can't await a socket write, so the release on the shutdown path has to be synchronous.

Plugins

none

Nikcli version

1.292.0 (also present on live-main today)

Steps to reproduce

1. Start herdr, open a pane, run nikcli. The agent panel shows a nikcli row.
2. Quit nikcli (ctrl+c) — back to the shell prompt, nikcli's process is gone.
3. herdr pane get <pane_id> still reports "agent":"nikcli", and the row is still in the panel.
4. Type exit in the shell. Only then does the row disappear — because the pane goes with it.

Screenshot and/or share link

Agent panel showing nikcli · 5 for a pane whose nikcli process has already exited (shell prompt visible in the pane).

Operating System

Windows 11 Home 26200

Terminal

WezTerm, inside a herdr pane (herdr 0.8.0-preview)

[SandroHub013]

Root cause is narrower than the description: it is Windows-only, and it is not the plugin.

shutdownWorker() in packages/nikcli/src/cli/cmd/tui/thread.ts takes the non-terminating branch on win32 — it unrefs the worker and fires the shutdown RPC without awaiting it. So Instance.disposeAll() never completes before the TUI process exits, and no plugin dispose runs. macOS and Linux await that call, which is why the row only sticks on Windows.

PR #233 releases from the TUI process after shutdownWorker() returns instead of relying on the worker.