Slash commands (/clear, /new, /undo, /reload-mcp) are dispatched from the
process_loop daemon thread. prompt_toolkit.run_in_terminal returns a
coroutine that only the main-thread event loop can drive, so calling it
from a daemon thread orphans the coroutine — the input prompt never
renders and user keystrokes leak into the composer instead of the
confirmation prompt (issue #23185).
Mirror the thread-aware guard already in _run_curses_picker: when off the
main thread, fall back to a direct input() call. Also wrap
run_in_terminal in try/except so WSL / Warp / other emulators that
silently drop the scheduled coroutine fall back to input() too.
Tests: tests/cli/test_prompt_text_input_thread_safety.py covers main
thread (run_in_terminal path), daemon thread (direct input fallback),
no-app, run_in_terminal-raises, and EOF handling.
