stop panning when the view loses focus

Holding A or D while a modal opened - the escape menu, a schematic choice, game
over - left the pan key held forever: the key-up went to the dialog and never
reached the view, so the world panned on its own once the dialog closed. Panning
runs on wall-clock time rather than ticks, so pausing did not mask it either.

Focus loss now drops every held action. This is a behaviour change, not a move,
so it is its own commit; it is only three lines because the input mapper already
owns the held state and can clear all of it at once.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JcReq7hVk4KUPhTDKWAG7K

src/ui/GameWorldView.cpp

@@ -18,6 +18,7 @@
 #include <QCursor>
 #include <QDir>
 #include <QFile>
+#include <QFocusEvent>
 #include <QFont>
 #include <QKeyEvent>
 #include <QLinearGradient>
@@ -2361,10 +2362,22 @@ void GameWorldView::keyReleaseEvent(QKeyEvent* event)
     }
     if (m_inputMapper.handleKeyRelease(event)) { return; }
     // Releasing Shift discards the copied building settings (REQ-BLD-COPY-CONFIG).
+    // Stays here rather than moving to the input mapper: Shift is the modifier of a
+    // mouse gesture, not a keyboard action of its own.
     if (event->key() == Qt::Key_Shift) { m_copiedConfig.reset(); }
     QOpenGLWidget::keyReleaseEvent(event);
 }
 
+void GameWorldView::focusOutEvent(QFocusEvent* event)
+{
+    // Without this, holding A while a modal opens (the escape menu, a schematic
+    // choice, game over) leaves the pan key held: the key-up goes to the dialog,
+    // never here, and the view pans on its own once the dialog closes. Panning runs
+    // on wall-clock time, so pausing does not mask it either.
+    m_inputMapper.releaseAll();
+    QOpenGLWidget::focusOutEvent(event);
+}
+
 void GameWorldView::mousePressEvent(QMouseEvent* event)
 {
     const WorldCoordinates coordinates = getCoordinates();

src/ui/GameWorldView.h

@@ -107,6 +107,10 @@ protected:
     void paintGL() override;
     void keyPressEvent(QKeyEvent* event) override;
     void keyReleaseEvent(QKeyEvent* event) override;
+    // Key-up never arrives for a key that was still held when focus moved away —
+    // to a modal dialog, another widget, or another window. Any held action would
+    // otherwise stay held forever, so focus loss drops all of them.
+    void focusOutEvent(QFocusEvent* event) override;
     void mousePressEvent(QMouseEvent* event) override;
     void mouseMoveEvent(QMouseEvent* event) override;
     void mouseReleaseEvent(QMouseEvent* event) override;