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.

shells/desktop/shell/qml/ShellState.qml

@@ -4,6 +4,9 @@ import QtQuick
 
 QtObject {
     property bool launcherOpen: false
+
+    // Focused-window tracking is a later compositor milestone. Launching an
+    // application does not mean it has focus, so this stays "Desktop" for now.
     property string activeApplication: "Desktop"
 
     function openLauncher() {
@@ -17,9 +20,4 @@ QtObject {
     function toggleLauncher() {
         launcherOpen = !launcherOpen
     }
-
-    function launch(name) {
-        activeApplication = name
-        closeLauncher()
-    }
 }