fix(snap): handle desktop runtime paths

Strict confinement uses a private runtime directory while the Wayland socket remains in the host directory. Resolve the accessible socket path, provide bundled XKB data, and fall back to X11 only when needed.

snap/local/open-cad-studio-wrapper

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+export XKB_CONFIG_ROOT="$SNAP/usr/share/X11/xkb"
+
+if [ -n "${WAYLAND_DISPLAY:-}" ]; then
+    case "$WAYLAND_DISPLAY" in
+        /*) wayland_socket="$WAYLAND_DISPLAY" ;;
+        *)
+            wayland_socket="$XDG_RUNTIME_DIR/$WAYLAND_DISPLAY"
+            host_socket="${XDG_RUNTIME_DIR%/*}/$WAYLAND_DISPLAY"
+            if [ ! -S "$wayland_socket" ] && [ -S "$host_socket" ]; then
+                WAYLAND_DISPLAY="$host_socket"
+                export WAYLAND_DISPLAY
+                wayland_socket="$host_socket"
+            fi
+            ;;
+    esac
+    [ -S "$wayland_socket" ] || unset WAYLAND_DISPLAY
+fi
+
+exec "$@"

snap/snapcraft.yaml

@@ -54,6 +54,7 @@ layout:
 apps:
   open-cad-studio:
     command-chain:
+      - bin/open-cad-studio-wrapper
       - bin/graphics-core22-wrapper
     command: usr/bin/OpenCADStudio
     desktop: usr/share/applications/io.github.HakanSeven12.OpenCadStudio.desktop
@@ -74,6 +75,8 @@ parts:
     override-build: |
       mkdir -p "${CRAFT_PART_INSTALL}"
       tar -xzf "${CRAFT_PROJECT_DIR}/linux-payload.tar.gz" -C "${CRAFT_PART_INSTALL}"
+      install -Dm755 "${CRAFT_PROJECT_DIR}/snap/local/open-cad-studio-wrapper" \
+        "${CRAFT_PART_INSTALL}/bin/open-cad-studio-wrapper"
     stage-packages:
       - libxcursor1
       - libxi6