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/DesktopEntry.hpp

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <QString>
+#include <QStringList>
+
+struct DesktopEntry
+{
+    QString desktopId;
+    QString filePath;
+    QString name;
+    QString genericName;
+    QString comment;
+    QString icon;
+    QString exec;
+    QString tryExec;
+    QString workingDirectory;
+    QStringList categories;
+    bool terminal = false;
+    bool hidden = false;
+    bool noDisplay = false;
+
+    bool isLauncherVisible() const;
+    bool launch() const;
+};
+
+DesktopEntry parseDesktopEntryFile(const QString &filePath, const QString &desktopId);
+QStringList applicationDirectories();
+QStringList currentDesktopIdentifiers();
+QStringList splitDesktopList(const QString &value);
+QStringList expandExec(const QString &exec, const DesktopEntry &entry);
+QString resolveIconName(const QString &icon);