Add desktop app service and VM dev session tooling

Introduces a new `core/applications` QML/C++ module (`Nebula.Applications`) to discover `.desktop` entries, expose filterable application models, and launch installed apps safely from the shell. The desktop launcher now uses real installed apps with themed icon loading and fallback glyphs, adds output-aware surface sizing via `OutputTracker`, and wires in image/icon providers. It also adds VMware-focused Sway/shell wrapper scripts, updates Sway config/session env defaults, and refreshes README docs to document the new development flow and Desktop 0.1 behavior.

core/applications/ApplicationService.hpp

@@ -0,0 +1,42 @@
+#pragma once
+
+#include "ApplicationFilterModel.hpp"
+#include "ApplicationModel.hpp"
+
+#include <QJSEngine>
+#include <QObject>
+#include <QQmlEngine>
+#include <QtQml/qqmlregistration.h>
+
+class ApplicationService : public QObject
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_SINGLETON
+    Q_PROPERTY(ApplicationModel *model READ model CONSTANT)
+    Q_PROPERTY(ApplicationFilterModel *filteredModel READ filteredModel CONSTANT)
+    Q_PROPERTY(QString filter READ filter WRITE setFilter NOTIFY filterChanged)
+    Q_PROPERTY(int count READ count NOTIFY countChanged)
+
+public:
+    explicit ApplicationService(QObject *parent = nullptr);
+    static ApplicationService *create(QQmlEngine *engine, QJSEngine *scriptEngine);
+
+    ApplicationModel *model() const;
+    ApplicationFilterModel *filteredModel() const;
+
+    QString filter() const;
+    void setFilter(const QString &filter);
+    int count() const;
+
+    Q_INVOKABLE bool launch(const QString &desktopId) const;
+    Q_INVOKABLE void refresh();
+
+signals:
+    void filterChanged();
+    void countChanged();
+
+private:
+    ApplicationModel *m_model = nullptr;
+    ApplicationFilterModel *m_filtered = nullptr;
+};