v0.1.16

Delivery acknowledgement for a send --enter

Prompts sent to agent sessions could be lost silently: dropped while the TUI was still booting, stuck unsent in the input box, or submitted to an agent that stayed idle. a send --enter now confirms each step on the rendered screen for Claude, Codex (and forks such as zcodex), and OpenCode:

• Ready: waits for a booting agent's input box before pasting (--ready-timeout, default 30s for new sessions).
• Landed: the input box must show the text or paste marker. A visibly dropped paste is resent (--resends, default 1).
• Submitted: the input box must clear after Enter. Up to 3 presses are made; text is never resent once it was seen.
• Working: within --wait-ack seconds (default 10), the agent must show a busy indicator, a harness working report, or transcript activity.

Exit codes: 0 delivered (or not verifiable for this engine), 3 delivered but the agent stayed idle, 1 failed. a --json send adds ack and a full delivery verdict. --no-ack restores fire-and-forget. Pane mail, deferred delivery and stdio-RPC sends share the ready, landed and submitted checks; the stdio send result carries delivery.

Also fixed: zcodex's input box was never recognized (its footer has no Context marker), so swallowed Enters were not retried there.

In live trials, sending right after a start lost the prompt on Claude, zcodex and OpenCode before this change. With it, all four engines delivered and replied.

Install: uv tool install aplexer==0.1.16 (or pip install aplexer==0.1.16).