fix(poteto-mode): close completed Herdr workers

[TiewKH]

Why

herdr-dispatch --wait returned a completed worker's output but left its pane open. Each caller had to remember a separate cleanup command, so completed workers could leak panes.

The dispatcher now reads the output and closes a verified done or idle worker. It leaves unfinished workers open and supports --keep-pane when a caller needs to inspect a completed worker.

Scope

• Add paneClosed to settled dispatch results.
• Close verified completed workers after reading their output.
• Fail the dispatch when completed-worker cleanup fails.
• Keep working, blocked, and unknown workers open.
• Update the real Herdr end-to-end check for the new lifecycle.
• Document the lifecycle in the README and Herdr execution guide.
• Release-stamp the Claude and Codex plugin manifests as 0.9.34.

Tradeoffs

--wait now closes completed panes by default. Callers that inspect a completed pane must pass --keep-pane.

Blast Radius

The change affects only Herdr dispatches that use --wait. Background dispatches and unfinished workers keep their current lifecycle.

Verification

• bun test passed all 147 dispatcher and vendored-tool tests.
• bun run typecheck passed.
• bun tools/generate.mjs passed and left the tree unchanged.
• bash -n tests/herdr-e2e.sh passed.
• Pinned Markdown lint passed for the changed Markdown files.
• A read-only Herdr review worker returned paneClosed as true. herdr pane list confirmed that its pane was absent.