fix(cli): preserve chat -q answer by gating exit-summary screen clear (#53009)

In single-query (-q) mode, the assistant's final answer was printed and
then immediately erased by _print_exit_summary() — which unconditionally
called _clear_terminal_on_exit() (ESC[3J ESC[2J ESC[H]). The answer was
present in the session store but invisible in the terminal.

The clear is only needed for interactive TUI teardown (#38928) where
prompt_toolkit chrome must be cleaned up. Add a clear_screen parameter
to _print_exit_summary() (default True, preserving interactive behavior)
and pass False from the single-query call site so the answer stays
visible above the exit summary.

Regression tests cover:
- clear_screen=True (default) calls _clear_terminal_on_exit()
- clear_screen=False skips the clear
- Single-query -q path passes False end-to-end
- Interactive path still clears (preserving #38928)

cli.py

@@ -12745,19 +12745,27 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin):
         except (Exception, KeyboardInterrupt) as e:
             logger.debug("Could not persist active CLI session before close: %s", e)
 
-    def _print_exit_summary(self):
-        """Print session resume info on exit, similar to Claude Code."""
-        # Clear the screen + scrollback before printing the summary so the
-        # live bottom chrome (status bar, input box, separator rules) and the
-        # rest of the session transcript don't get stranded above the exit
-        # summary (#38252). By this point app.run() has returned and
-        # prompt_toolkit has restored terminal modes, so writing raw escapes
-        # to stdout is safe. ESC[3J clears scrollback, ESC[2J clears the
-        # visible screen, ESC[H homes the cursor — so the summary prints at a
-        # clean top-left. Falls back to the platform clear command if stdout
-        # isn't a TTY-capable stream. Honors NO_COLOR/dumb terminals by
-        # skipping silently when there's no real console.
-        self._clear_terminal_on_exit()
+    def _print_exit_summary(self, clear_screen: bool = True):
+        """Print session resume info on exit, similar to Claude Code.
+
+        Args:
+            clear_screen: When True (default), clear the terminal screen and
+                scrollback before printing the summary. This is appropriate for
+                interactive TUI teardown (#38252). Single-query (-q) mode should
+                pass False to preserve the printed answer (#53009).
+        """
+        if clear_screen:
+            # Clear the screen + scrollback before printing the summary so the
+            # live bottom chrome (status bar, input box, separator rules) and the
+            # rest of the session transcript don't get stranded above the exit
+            # summary (#38252). By this point app.run() has returned and
+            # prompt_toolkit has restored terminal modes, so writing raw escapes
+            # to stdout is safe. ESC[3J clears scrollback, ESC[2J clears the
+            # visible screen, ESC[H homes the cursor — so the summary prints at a
+            # clean top-left. Falls back to the platform clear command if stdout
+            # isn't a TTY-capable stream. Honors NO_COLOR/dumb terminals by
+            # skipping silently when there's no real console.
+            self._clear_terminal_on_exit()
         print()
         msg_count = len(self.conversation_history)
         if msg_count > 0:
@@ -16171,7 +16179,7 @@ def main(
                 # banner, doesn't depend on the welcome banner being shown.
                 cli._show_security_advisories()
                 cli.chat(query, images=single_query_images or None)
-                cli._print_exit_summary()
+                cli._print_exit_summary(clear_screen=False)
         finally:
             _finalize_single_query(cli)
         return