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.

compositor/sway/dev/run-sway-vm.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+# Recommended VMware development session entry point.
+#
+# Sets compositor-side development environment (cursor theme, software
+# cursors if needed) and starts Sway with the Nebula development config.
+# Sway then autostarts nebula-shell via scripts/run-nebula-vm.sh.
+#
+# Usage:
+#   ./compositor/sway/dev/run-sway-vm.sh
+#
+# Equivalent:
+#   export XCURSOR_THEME=Adwaita XCURSOR_SIZE=24
+#   sway -c compositor/sway/nebula-sway.conf
+#
+# Skip shell autostart:
+#   NEBULA_SHELL_AUTOSTART=0 ./compositor/sway/dev/run-sway-vm.sh
+
+set -eu
+
+script_dir=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+repo_root=$(CDPATH= cd -- "${script_dir}/../../.." && pwd)
+config="${repo_root}/compositor/sway/nebula-sway.conf"
+
+export XDG_CURRENT_DESKTOP="${XDG_CURRENT_DESKTOP:-NebulaOS}"
+export XDG_SESSION_DESKTOP="${XDG_SESSION_DESKTOP:-nebula}"
+export XCURSOR_THEME="${XCURSOR_THEME:-Adwaita}"
+export XCURSOR_SIZE="${XCURSOR_SIZE:-24}"
+
+# VMware often needs software cursors. This is development-specific.
+export WLR_NO_HARDWARE_CURSORS="${WLR_NO_HARDWARE_CURSORS:-1}"
+
+if [ ! -f "${config}" ]; then
+    echo "nebula: missing Sway config at ${config}" >&2
+    exit 1
+fi
+
+cd "${repo_root}"
+echo "nebula: starting Sway with ${config}"
+exec sway -c "${config}" "$@"