fix(cli): drive _prompt_text_input directly when off main thread (#23454)

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.

cli.py

@@ -6008,7 +6008,17 @@ class HermesCLI:
         return result[0]
 
     def _prompt_text_input(self, prompt_text: str) -> str | None:
-        """Prompt for free-text input safely inside or outside prompt_toolkit."""
+        """Prompt for free-text input safely inside or outside prompt_toolkit.
+
+        Mirrors the thread-aware guard in ``_run_curses_picker``: ``run_in_terminal``
+        returns a coroutine that must be awaited by the prompt_toolkit event loop,
+        which only exists on the main thread.  Slash commands are dispatched from
+        the ``process_loop`` daemon thread (see issue #23185), so calling
+        ``run_in_terminal`` from there orphans the coroutine — ``_ask`` never runs,
+        and user keystrokes leak into the composer instead.  Fall back to a direct
+        ``input()`` when we're off the main thread.
+        """
+        import threading
         result = [None]
 
         def _ask():
@@ -6017,13 +6027,23 @@ class HermesCLI:
             except (KeyboardInterrupt, EOFError):
                 pass
 
-        if self._app:
+        in_main_thread = threading.current_thread() is threading.main_thread()
+
+        if self._app and in_main_thread:
             from prompt_toolkit.application import run_in_terminal
             was_visible = self._status_bar_visible
             self._status_bar_visible = False
             self._app.invalidate()
             try:
                 run_in_terminal(_ask)
+            except Exception:
+                # WSL / Warp / certain terminal emulators silently drop the
+                # scheduled coroutine.  Fall back to a direct input() so the
+                # user's keystrokes don't leak into the agent buffer.
+                try:
+                    _ask()
+                except Exception:
+                    pass
             finally:
                 self._status_bar_visible = was_visible
                 self._app.invalidate()