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

tests/cli/test_chat_q_exit_clear.py

@@ -0,0 +1,149 @@
+"""Regression tests for #53009: chat -q final response erased by exit-summary clear."""
+
+from types import SimpleNamespace
+
+import pytest
+
+import cli as cli_mod
+
+
+# ── A3.1 Test-First: verify _clear_terminal_on_exit gating ──────────────────
+
+def test_print_exit_summary_clears_screen_by_default(monkeypatch):
+    """Default behavior: _print_exit_summary() calls _clear_terminal_on_exit()."""
+    calls = []
+
+    class FakeCLI:
+        conversation_history = []
+        session_start = None
+
+        def _clear_terminal_on_exit(self):
+            calls.append("clear")
+
+    monkeypatch.setattr(cli_mod, "datetime", SimpleNamespace(
+        now=lambda: SimpleNamespace(
+            __sub__=lambda self, other: SimpleNamespace(
+                total_seconds=lambda: 0
+            )
+        )
+    ))
+
+    fake = FakeCLI()
+    cli_mod.HermesCLI._print_exit_summary(fake)  # default clear_screen=True
+
+    assert "clear" in calls, "_clear_terminal_on_exit should be called by default"
+
+
+def test_print_exit_summary_skips_clear_when_clear_screen_false(monkeypatch):
+    """With clear_screen=False, _print_exit_summary() does NOT clear."""
+    calls = []
+
+    class FakeCLI:
+        conversation_history = []
+        session_start = None
+
+        def _clear_terminal_on_exit(self):
+            calls.append("clear")
+
+    monkeypatch.setattr(cli_mod, "datetime", SimpleNamespace(
+        now=lambda: SimpleNamespace(
+            __sub__=lambda self, other: SimpleNamespace(
+                total_seconds=lambda: 0
+            )
+        )
+    ))
+
+    fake = FakeCLI()
+    cli_mod.HermesCLI._print_exit_summary(fake, clear_screen=False)
+
+    assert "clear" not in calls, (
+        "_clear_terminal_on_exit should NOT be called when clear_screen=False"
+    )
+
+
+# ── Production-path test: single-query -q path skips the clear ──────────────
+
+def test_single_query_main_skips_clear_on_exit_summary(monkeypatch):
+    """The single-query (-q) path calls _print_exit_summary without clearing."""
+    calls = []
+    clear_calls = []
+
+    class FakeCLI:
+        def __init__(self, **_kwargs):
+            self.console = SimpleNamespace(print=lambda *_a, **_kw: calls.append("query-label"))
+            self.session_id = "sq-test"
+            self.agent = SimpleNamespace(
+                session_id="sq-test",
+                platform="cli",
+            )
+
+        def _claim_active_session(self, surface, *, stderr=False):
+            calls.append(("claim", surface, stderr))
+            return True
+
+        def _show_security_advisories(self):
+            calls.append("advisories")
+
+        def chat(self, query, images=None):
+            calls.append(("chat", query, images))
+            return "done"
+
+        def _print_exit_summary(self, clear_screen=True):
+            calls.append(("summary", clear_screen))
+            if clear_screen:
+                clear_calls.append("CLEARED")  # should NOT happen
+
+    monkeypatch.setattr(cli_mod, "HermesCLI", FakeCLI)
+    monkeypatch.setattr(cli_mod.atexit, "register", lambda *_a, **_kw: None)
+    monkeypatch.setattr(
+        cli_mod,
+        "_finalize_single_query",
+        lambda fake_cli: calls.append(("finalize", fake_cli.session_id)),
+    )
+
+    cli_mod.main(query="hello", quiet=False, toolsets="terminal")
+
+    assert calls == [
+        ("claim", "cli", False),
+        "query-label",
+        "advisories",
+        ("chat", "hello", None),
+        ("summary", False),  # <-- clear_screen=False for single-query
+        ("finalize", "sq-test"),
+    ]
+    assert len(clear_calls) == 0, (
+        "_clear_terminal_on_exit must NOT be called in single-query mode"
+    )
+
+
+# ── Verify interactive mode still clears ────────────────────────────────────
+
+def test_print_exit_summary_still_clears_in_interactive_path(monkeypatch):
+    """Interactive mode should still clear the screen (preserving #38928)."""
+    from datetime import datetime as real_datetime
+
+    calls = []
+
+    class FakeCLI:
+        conversation_history = [
+            {"role": "user", "content": "hello"},
+            {"role": "assistant", "content": "hi"},
+        ]
+        session_start = real_datetime(2026, 1, 1, 12, 0, 0)
+        session_id = "test-session"
+        _session_db = None
+        agent = None
+
+        def _clear_terminal_on_exit(self):
+            calls.append("clear")
+
+    monkeypatch.setattr(cli_mod, "datetime", SimpleNamespace(
+        now=lambda: real_datetime(2026, 1, 1, 12, 1, 0)  # 1 min elapsed
+    ))
+
+    fake = FakeCLI()
+    cli_mod.HermesCLI._print_exit_summary(fake)  # default clear_screen=True
+
+    assert "clear" in calls, (
+        "Interactive mode should still clear the screen (regression test for #38928)"
+    )