Fix Flatpak crash on Wayland by requiring X11/XWayland socket

- Upgrade runtime from 23.08 to 24.08 for security updates
- Replace --socket=wayland and --socket=fallback-x11 with --socket=x11
- Avalonia 11 requires XWayland on Wayland desktops (no native Wayland yet)
- The fallback-x11 socket only provides X11 on X11 desktops, causing
  XOpenDisplay failures in Flatpak sandboxes on Wayland sessions

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: chrisuthe

packaging/flatpak/io.sendspin.client.yml

@@ -15,18 +15,16 @@
 
 app-id: io.sendspin.client
 runtime: org.freedesktop.Platform
-runtime-version: '23.08'
+runtime-version: '24.08'
 sdk: org.freedesktop.Sdk
 
 command: SendspinClient.Linux
 
 # Sandbox permissions
 finish-args:
-  # Display access (X11 and Wayland)
+  # Display access - X11/XWayland required (Avalonia uses XWayland on Wayland desktops)
   - --share=ipc
   - --socket=x11
-  - --socket=wayland
-  - --socket=fallback-x11
 
   # Audio access (PipeWire/PulseAudio)
   - --socket=pulseaudio