diff --git a/src/gui_2.py b/src/gui_2.py
index d80a1ef4..6f5ebba0 100644
--- a/src/gui_2.py
+++ b/src/gui_2.py
@@ -698,6 +698,11 @@ class App:
    self.runner_params.callbacks.post_init             = _profiled_post_init
    self._fetch_models(self.current_provider)
    md_options = markdown_helper.get_renderer().options
+   pre_install_result: Result[bool] = _install_default_layout_pre_run_result(self)
+   if not pre_install_result.ok:
+    err = pre_install_result.errors[0]
+    if hasattr(self, "_startup_timeline_errors"):
+     self._startup_timeline_errors.append(("_install_default_layout_pre_run", err))
    run_result = _run_immapp_result(self)
    if not run_result.ok:
     err = run_result.errors[0]
@@ -1488,7 +1493,8 @@ def _install_default_layout_if_empty(src_ini: Path, dst_ini: Path) -> Result[boo
  legacy wrapper in App._post_init can drain to _startup_timeline_errors.
 
  [C: src/gui_2.py:_install_default_layout_if_empty_result,
-     src/gui_2.py:App._post_init]"""
+     src/gui_2.py:App._post_init,
+     src/gui_2.py:App.run (pre-immapp disk write)]"""
  try:
   dst_text: str = dst_ini.read_text(encoding="utf-8", errors="replace") if dst_ini.exists() else ""
  except OSError:
@@ -1532,6 +1538,56 @@ def _install_default_layout_if_empty_result(app: "App", src: Path, dst: Path) ->
 
  [C: src/gui_2.py:_install_default_layout_if_empty, src/gui_2.py:App._post_init]"""
  return _install_default_layout_if_empty(src, dst)
+
+
+def _install_default_layout_pre_run_result(app: "App") -> Result[bool]:
+ """Pre-immapp.run disk-only install for App.run entry point.
+
+ HelloImGui loads `runner_params.ini_filename` from disk BEFORE the
+ post_init callback fires (imgui.load_ini_settings_from_disk runs in
+ the load_user_pref phase before callback dispatch). So writing to cwd
+ after post_init is too late for this session.
+
+ This drains the same helper but skips the live-session apply
+ (load_ini_settings_from_memory) because imgui is not yet initialized
+ when App.run calls this before _run_immapp_result. The disk write is
+ what matters -- HelloImGui then reads it as its initial state.
+
+ Returns Result[data=True] when installed, Result[data=False] when
+ skipped (existing valid INI).
+
+ [C: src/gui_2.py:App.run, src/gui_2.py:App._post_init]"""
+ from src.layouts import get_layouts_dir
+ src_path: Path = get_layouts_dir() / "default.ini"
+ dst_path: Path = Path.cwd() / "manualslop_layout.ini"
+ try:
+  dst_text: str = dst_path.read_text(encoding="utf-8", errors="replace") if dst_path.exists() else ""
+ except OSError:
+  dst_text = ""
+ is_empty: bool = len(dst_text) < 1000 or "[Window][" not in dst_text
+ if not is_empty:
+  return Result(data=False)
+ try:
+  src_text: str = src_path.read_text(encoding="utf-8", errors="replace")
+ except OSError as e:
+  return Result(data=False, errors=[ErrorInfo(
+   kind=ErrorKind.INTERNAL,
+   message=f"Could not read bundled layout {src_path}: {e}",
+   source="gui_2._install_default_layout_pre_run_result",
+   original=e,
+  )])
+ try:
+  dst_path.parent.mkdir(parents=True, exist_ok=True)
+  dst_path.write_text(src_text, encoding="utf-8")
+ except OSError as e:
+  return Result(data=False, errors=[ErrorInfo(
+   kind=ErrorKind.INTERNAL,
+   message=f"Could not write layout {dst_path}: {e}",
+   source="gui_2._install_default_layout_pre_run_result",
+   original=e,
+  )])
+ sys.stderr.write(f"[GUI] pre-run installed default layout: {src_path} -> {dst_path}\n")
+ return Result(data=True)
 def _run_immapp_result(app: "App") -> Result[None]:
  """Drain-aware variant of App.run immapp.run() call (L728 INTERNAL_SILENT_SWALLOW).
 
diff --git a/tests/test_default_layout_install.py b/tests/test_default_layout_install.py
index 7496c66d..e968e294 100644
--- a/tests/test_default_layout_install.py
+++ b/tests/test_default_layout_install.py
@@ -48,12 +48,15 @@ def _read_launch_log(log_suffix: str) -> str:
   return ""
 
 
-def _assert_live_session_apply(log_suffix: str) -> None:
+def _assert_install_applied(log_suffix: str) -> None:
  text: str = _read_launch_log(log_suffix)
- assert "and applied to live session" in text, (
-  f"install write succeeded but live-session apply did not happen; "
-  f"expected the live-apply confirmation line in stderr, got: "
-  f"{[l for l in text.splitlines() if 'installed' in l]!r}"
+ install_msgs: list[str] = [l for l in text.splitlines() if "pre-run installed" in l or "applied to live session" in l]
+ assert install_msgs, (
+  f"install was not invoked for this run; expected one of "
+  f"'[GUI] pre-run installed default layout: ...' or "
+  f"'[GUI] installed default layout: ... (and applied to live session)' "
+  f"in stderr, got install-related lines: "
+  f"{[l for l in text.splitlines() if 'default layout' in l]!r}"
  )
 
 
@@ -185,7 +188,7 @@ def test_default_layout_installed_when_ini_missing(tmp_path: Path) -> None:
  proc: subprocess.Popen = _start_subprocess_in(workspace, "ini_missing")
  try:
   _assert_installed_default(workspace)
-  _assert_live_session_apply("ini_missing")
+  _assert_install_applied("ini_missing")
  finally:
   _terminate(proc)
   shutil.rmtree(workspace, ignore_errors=True)
@@ -199,7 +202,7 @@ def test_default_layout_installed_when_ini_empty(tmp_path: Path) -> None:
  proc: subprocess.Popen = _start_subprocess_in(workspace, "ini_empty")
  try:
   _assert_installed_default(workspace)
-  _assert_live_session_apply("ini_empty")
+  _assert_install_applied("ini_empty")
  finally:
   _terminate(proc)
   shutil.rmtree(workspace, ignore_errors=True)