plannotator-tui: hand a document to the human for review

Only when HERDR_ENV=1 (you are running inside Herdr). Otherwise tell the human where the file is and ask them to review it.

1. Write the document to a file. Do not paste it into chat as well.

2. Open it for review, from your own pane:

   plannotator-tui herdr open docs/plans/auth.md
   

   Copy

   plannotator-tui opens beside you (or wherever the user configured it), already knowing that feedback comes back to this pane.

3. End your turn. Do not wait, poll, or read the pane. The review arrives as the next user message, as numbered feedback:

   ## 1. (line 12) Feedback on: "Rotate the token on every…"
   > Rotation on every privilege change will log people out…
   

   Copy

   Address every item, then continue.

When you list files you want the human to open, you may print them as file:// hyperlinks (OSC 8):

printf '\e]8;;file://%s\e\\%s\e]8;;\e\\\n' "$PWD/docs/plans/auth.md" "docs/plans/auth.md"

Do not promise that Ctrl-click opens them in plannotator-tui. That happens only when the human installed the opt-in annotate-links add-on. To ask for a review, use step 2.

If plannotator-tui is not on PATH, the raw Herdr command is:

herdr plugin pane open --plugin annotate --entrypoint doc --placement split \
  --direction right --target-pane "$HERDR_PANE_ID" --focus --cwd "$PWD" \
  --env PLANNOTATOR_TUI_FILE="$PWD/docs/plans/auth.md" --env PLANNOTATOR_TUI_DELIVER_TO="$HERDR_PANE_ID"