tui: a failed playbook live edit is swallowed — no message, no retry, no re-sync #1089

The TUI's per-keystroke Playbook sync discards the daemon's answer when it is an error:

let Ok(result) = self.client.playbook_edit(params).await else {
    return;
};

(crates/cli/src/app/editor.rs ~line 1526 @ ad47152)

The edit is anchored (old_string → new_string, playbook_anchored_live_edit), so it fails whenever the daemon's document no longer contains that anchor — after a local undo (#1088), or when an agent rewrites the region you are typing in between two keystrokes. When it fails:

• no status message,
• no retry,
• no re-fetch,
• and popup.saved_markdown is left stale, so playbook_popup_has_unsaved_edits is now true and on_playbook_state stops adopting remote changes (crates/cli/src/app.rs ~line 10155) — by design, to protect unsaved work.

The net effect is a Playbook that silently stops both publishing and receiving. Every later keystroke fails against the same stale anchor. The only signal is the * modified chip in the pane title, which reads as ordinary "you have unsaved edits", not "your last 40 keystrokes are not in the document".

Repro

1. Open a Playbook in the TUI, type a few characters (synced).
2. Force an anchor mismatch — press C-x u (tui: playbook undo (C-x u) never reaches the daemon, then every later keystroke is silently dropped #1088), or have an agent rewrite the line under the caret.
3. Keep typing.

Observed: the TUI buffer advances, the daemon's document does not, and an agent edit made afterwards does not appear in the TUI.

Expected

A failed live edit is a recoverable conflict, not a terminal state. The merge machinery already exists and works: C-x C-s on the same diverged buffer produced playbook merged with agent edits (version 42) with both sides intact.

Suggested fix

On playbook_edit error, fall back to the save/3-way-merge path (optionally after one retry with a re-fetched base), and surface a short status. That single change also bounds the blast radius of #1088 to one lost character.

Acceptance criteria

• A failed live edit produces a visible status message.
• The client re-converges with the daemon automatically (merge or rebase) rather than staying diverged until a manual C-x C-s.
• Regression test: a live edit whose anchor is missing server-side still ends with client and daemon documents equal.

Found during a hands-on UX audit of the Playbook in the TUI and web UI.