fix(cli): let redraw recovery rebuild scrollback

cli.py

@@ -501,6 +501,12 @@ def load_cli_config() -> Dict[str, Any]:
             "busy_input_mode": "interrupt",
             "persistent_output": True,
             "persistent_output_max_lines": 200,
+            # Clear terminal scrollback as well as the visible viewport when the
+            # classic CLI performs a full redraw/resize recovery. Disabled by
+            # default because some users prefer preserving terminal history;
+            # enable when a terminal/tmux stack stamps stale prompt chrome into
+            # scrollback during fullscreen/restore resizes.
+            "cli_rebuild_scrollback_on_redraw": False,
             # Print a one-line summary of resolved modal prompts (approval /
             # clarify) into scrollback so the decision survives the repaint.
             "persist_prompts": True,
@@ -5013,13 +5019,34 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin, CLIBillingMixin):
         app = getattr(self, "_app", None)
         if not app:
             return
-        self._clear_prompt_toolkit_screen(app)
+        self._clear_prompt_toolkit_screen(
+            app,
+            rebuild_scrollback=self._redraw_rebuilds_scrollback(),
+        )
         _replay_output_history()
         try:
             app.invalidate()
         except Exception:
             pass
 
+    @staticmethod
+    def _redraw_rebuilds_scrollback() -> bool:
+        """Return whether CLI redraw/resize recovery should clear scrollback.
+
+        Some terminal/tmux stacks move prompt_toolkit's non-fullscreen bottom
+        chrome into scrollback when the window is maximized/restored. A normal
+        CSI 2J viewport clear cannot remove those stale prompt/input-rule rows,
+        so users who hit that class of bug need CSI 3J as well, followed by the
+        existing bounded output-history replay.
+        """
+        display_config = CLI_CONFIG.get("display") if isinstance(CLI_CONFIG, dict) else {}
+        if not isinstance(display_config, dict):
+            display_config = {}
+        raw = display_config.get("cli_rebuild_scrollback_on_redraw", False)
+        if isinstance(raw, str):
+            return raw.strip().lower() in {"1", "true", "yes", "on", "always"}
+        return bool(raw)
+
     def _recover_terminal_after_interrupt(self) -> None:
         """Recover the terminal after an interrupted agent turn (#33271).
 
@@ -5160,7 +5187,10 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin, CLIBillingMixin):
         )
         if width_changed:
             try:
-                self._clear_prompt_toolkit_screen(app, rebuild_scrollback=False)
+                self._clear_prompt_toolkit_screen(
+                    app,
+                    rebuild_scrollback=self._redraw_rebuilds_scrollback(),
+                )
                 _replay_output_history()
             except Exception:
                 pass

hermes_cli/config_defaults.py

@@ -1214,6 +1214,12 @@ DEFAULT_CONFIG = {
         # behaves badly with replayed scrollback.
         "persistent_output": True,
         "persistent_output_max_lines": 200,
+        # Clear terminal scrollback as well as the visible viewport when the
+        # classic CLI performs a full redraw/resize recovery. Disabled by
+        # default because some users prefer preserving terminal history;
+        # enable when a terminal/tmux stack stamps stale prompt chrome into
+        # scrollback during fullscreen/restore window transitions.
+        "cli_rebuild_scrollback_on_redraw": False,
         # Print a one-line summary of resolved modal prompts (approval /
         # clarify) into scrollback so the question and decision survive the
         # panel repaint. Set false to keep scrollback untouched.

tests/cli/test_cli_force_redraw.py

@@ -53,6 +53,11 @@ class TestForceFullRedraw:
         monkeypatch.setattr(bare_cli, "_get_tui_terminal_width", lambda: 90)
         monkeypatch.setattr(bare_cli, "_schedule_status_bar_unsuppress", lambda *_: None)
         monkeypatch.setattr(cli_mod, "_replay_output_history", lambda: events.append("replay"))
+        monkeypatch.setattr(
+            cli_mod,
+            "CLI_CONFIG",
+            {"display": {"cli_rebuild_scrollback_on_redraw": False}},
+        )
 
         bare_cli._recover_after_resize(app, original_on_resize)
 
@@ -66,6 +71,57 @@ class TestForceFullRedraw:
         assert bare_cli._last_resize_width == 90
         assert bare_cli._status_bar_suppressed_after_resize is True
 
+    def test_force_redraw_uses_full_screen_clear_without_scrollback_clear(self, bare_cli, monkeypatch):
+        app = MagicMock()
+        bare_cli._app = app
+        monkeypatch.setattr(
+            cli_mod,
+            "CLI_CONFIG",
+            {"display": {"cli_rebuild_scrollback_on_redraw": False}},
+        )
+
+        bare_cli._force_full_redraw()
+
+        app.renderer.output.erase_screen.assert_called_once()
+        app.renderer.output.cursor_goto.assert_called_once_with(0, 0)
+        app.renderer.output.write_raw.assert_not_called()
+
+    def test_force_redraw_can_clear_scrollback_when_configured(self, bare_cli, monkeypatch):
+        app = MagicMock()
+        bare_cli._app = app
+        monkeypatch.setattr(
+            cli_mod,
+            "CLI_CONFIG",
+            {"display": {"cli_rebuild_scrollback_on_redraw": True}},
+        )
+
+        bare_cli._force_full_redraw()
+
+        app.renderer.output.erase_screen.assert_called_once()
+        app.renderer.output.write_raw.assert_called_once_with("\x1b[3J")
+
+    def test_resize_recovery_can_clear_scrollback_when_configured(self, bare_cli, monkeypatch):
+        app = MagicMock()
+        events = []
+        app.renderer.output.erase_screen.side_effect = lambda: events.append("erase")
+        app.renderer.output.write_raw.side_effect = lambda *_: events.append("scrollback_wipe")
+        original_on_resize = lambda: events.append("original_resize")
+
+        bare_cli._status_bar_suppressed_after_resize = False
+        bare_cli._last_resize_width = 200
+        monkeypatch.setattr(bare_cli, "_get_tui_terminal_width", lambda: 90)
+        monkeypatch.setattr(bare_cli, "_schedule_status_bar_unsuppress", lambda *_: None)
+        monkeypatch.setattr(cli_mod, "_replay_output_history", lambda: events.append("replay"))
+        monkeypatch.setattr(
+            cli_mod,
+            "CLI_CONFIG",
+            {"display": {"cli_rebuild_scrollback_on_redraw": "true"}},
+        )
+
+        bare_cli._recover_after_resize(app, original_on_resize)
+
+        assert events[:3] == ["erase", "scrollback_wipe", "replay"]
+        assert events.index("scrollback_wipe") < events.index("original_resize")
 
     def test_resize_recovery_is_debounced(self, bare_cli, monkeypatch):
         timers = []