tmux capture-pane strips the ⬇ (U+2B07) character; grep on it always
returns empty. Switch to case-insensitive text matching on actual
LLM response content (hello, hi, greeting, hey).
Also: reorder tests (cascade-parsing, eval-command, status-bar first
to warm the TUI; agent-responds last), increase handshake timeout
to 60s, increase agent poll timeout to 90s.
TUI integration: 5/5 pass (was 4/5 with false-negative on agent-responds)
