Disable minimap rotation by default and fix settings checkbox

Changed default value from true to false in three places:
- Minimap class (rotateWithCamera member)
- GameScreen settings (minimapRotate_ and pendingMinimapRotate)
- Restore Interface Defaults button

The minimap will now remain fixed/north-up by default, and the settings
checkbox properly controls the rotation behavior.

src/ui/game_screen.cpp

@@ -4145,7 +4145,7 @@ void GameScreen::renderSettingsWindow() {
         ImGui::Checkbox("Rotate Minimap", &pendingMinimapRotate);
         if (ImGui::Button("Restore Interface Defaults", ImVec2(-1, 0))) {
             pendingUiOpacity = 65;
-            pendingMinimapRotate = true;
+            pendingMinimapRotate = false;
         }
 
         ImGui::Spacing();