refactor(gui_2): migrate L1222 _show_menus is_max to Result[T] (Phase 3)

TIER-2 READ conductor/code_styleguides/error_handling.md end-to-end before Phase 3.

Adds _show_menus_is_max_result(app, hwnd) -> Result[bool] helper that wraps
the win32gui.GetWindowPlacement try/except from App._show_menus. The data
field carries the is_max value (True iff window is maximized, False on
failure) so the legacy wrapper can use it without an additional instance
attribute.

App._show_menus becomes a thin wrapper that drains errors to
_last_request_errors when GetWindowPlacement fails.

Audit: BROAD_CATCH count 20 -> 19, COMPLIANT count 17 -> 18. Tests: 2/2 pass.

src/gui_2.py

@@ -1211,9 +1211,11 @@ class App:
       win32gui.SendMessage(hwnd, win32con.WM_NCLBUTTONDOWN, win32con.HTCAPTION, 0)
     
     imgui.push_style_color(imgui.Col_.button, imgui.ImVec4(0, 0, 0, 0))
-    #Note(Ed): Exception(Thirdparty)
-    try:              is_max = win32gui.GetWindowPlacement(hwnd)[1] == win32con.SW_SHOWMAXIMIZED
-    except Exception: is_max = False
+    result = _show_menus_is_max_result(self, hwnd)
+    if not result.ok:
+     if not hasattr(self, '_last_request_errors'): self._last_request_errors = []
+     self._last_request_errors.append(("_show_menus.is_max", result.errors[0]))
+    is_max = result.data
     # Explicitly set Y to 0 and match button height to bar height for perfect alignment
     imgui.set_cursor_pos((right_x, 0))
     if imgui.button("_", (btn_w, bar_h)):                       win32gui.ShowWindow(hwnd, win32con.SW_MINIMIZE)
@@ -7554,6 +7556,33 @@ def _show_menus_hwnd_result(app: "App") -> Result[int]:
    original=e,
   )])
 
+def _show_menus_is_max_result(app: "App", hwnd) -> Result[bool]:
+ """Drain-aware variant of L1222 _show_menus GetWindowPlacement try/except.
+
+ Extracts the win32gui.GetWindowPlacement try/except from App._show_menus
+ into a Result-returning helper. On success, returns Result(data=is_max)
+ where is_max is True iff the window is currently maximized. On
+ failure, returns Result(data=False, errors=[ErrorInfo]) - the data
+ defaults to False (not maximized) matching the original except
+ branch behavior.
+
+ [C: src/gui_2.py:App._show_menus (L1222 legacy wrapper)]
+ """
+ global win32gui, win32con
+ try:
+  if win32gui is None:
+   import win32gui
+   import win32con
+  is_max = win32gui.GetWindowPlacement(hwnd)[1] == win32con.SW_SHOWMAXIMIZED
+  return Result(data=is_max)
+ except Exception as e:
+  return Result(data=False, errors=[ErrorInfo(
+   kind=ErrorKind.INTERNAL,
+   message=f"GetWindowPlacement failed for hwnd={hwnd}: {e}",
+   source="gui_2._show_menus_is_max_result",
+   original=e,
+  )])
+
 #endregion: Phase 3 Render-Loop Result Helpers
 
 #endregion: MMA