Floating polish: visibility, resize, saved geometry, D-Bus, desktop entry

- VisibilityController: show on field focus, dismiss until next focus,
  manual show/hide/toggle overrides
- FloatingWindow: resize from the corner grip, clamp to screen
- WindowSettings: geometry per screen, debounced saves
- DBusControl: org.sloposk.Keyboard Show/Hide/Toggle for global shortcuts
- org.sloposk.keyboard.desktop so System Settings lists it as a virtual keyboard
- README with build/run/layout docs

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/app/DBusControl.cpp

@@ -0,0 +1,22 @@
+#include "DBusControl.h"
+
+#include "window/VisibilityController.h"
+
+#include <QDBusConnection>
+
+DBusControl::DBusControl(VisibilityController &visibility, QObject *parent)
+    : QObject(parent)
+    , m_visibility(visibility)
+{
+}
+
+bool DBusControl::registerOnSessionBus()
+{
+    QDBusConnection bus = QDBusConnection::sessionBus();
+    return bus.registerService(QStringLiteral("org.sloposk.Keyboard"))
+           && bus.registerObject(QStringLiteral("/Keyboard"), this, QDBusConnection::ExportScriptableSlots);
+}
+
+void DBusControl::Show() { m_visibility.show(); }
+void DBusControl::Hide() { m_visibility.hide(); }
+void DBusControl::Toggle() { m_visibility.toggle(); }

src/app/DBusControl.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <QObject>
+
+class VisibilityController;
+
+// Session-bus remote control, e.g. for a global shortcut:
+//   qdbus org.sloposk.Keyboard /Keyboard org.sloposk.Keyboard.Toggle
+class DBusControl : public QObject
+{
+    Q_OBJECT
+    Q_CLASSINFO("D-Bus Interface", "org.sloposk.Keyboard")
+
+public:
+    explicit DBusControl(VisibilityController &visibility, QObject *parent = nullptr);
+
+    // False if the bus is unavailable or another instance owns the name.
+    bool registerOnSessionBus();
+
+public Q_SLOTS:
+    Q_SCRIPTABLE void Show();
+    Q_SCRIPTABLE void Hide();
+    Q_SCRIPTABLE void Toggle();
+
+private:
+    VisibilityController &m_visibility;
+};

src/app/DevHooks.cpp

@@ -0,0 +1,38 @@
+#include "DevHooks.h"
+
+#include "backend/TextBackend.h"
+
+#include <QCoreApplication>
+#include <QQuickWindow>
+#include <QTimer>
+
+namespace {
+
+void installAutotype(TextBackend &backend, const QString &text)
+{
+    QObject::connect(&backend, &TextBackend::activeChanged, &backend, [&backend, text] {
+        if (backend.isActive())
+            backend.commitText(text);
+    });
+}
+
+void installScreenshot(QQuickWindow &window, const QString &path)
+{
+    constexpr int SettleMs = 500;
+    QTimer::singleShot(SettleMs, &window, [&window, path] {
+        const bool saved = window.grabWindow().save(path);
+        if (!saved)
+            qWarning("Failed to save screenshot to %s", qPrintable(path));
+        QCoreApplication::exit(saved ? 0 : 1);
+    });
+}
+
+} // namespace
+
+void installDevHooks(TextBackend &backend, QQuickWindow &window)
+{
+    if (const QString text = qEnvironmentVariable("SLOPOSK_AUTOTYPE"); !text.isEmpty())
+        installAutotype(backend, text);
+    if (const QString path = qEnvironmentVariable("SLOPOSK_SCREENSHOT"); !path.isEmpty())
+        installScreenshot(window, path);
+}

src/app/DevHooks.h

@@ -0,0 +1,9 @@
+#pragma once
+
+class QQuickWindow;
+class TextBackend;
+
+// Environment-driven helpers for headless testing; no effect when unset.
+//   SLOPOSK_AUTOTYPE=text    commit `text` whenever a text field gets focus
+//   SLOPOSK_SCREENSHOT=path  save the keyboard window to `path`, then quit
+void installDevHooks(TextBackend &backend, QQuickWindow &window);