Fix wallpaper persistence, tray icons, Booru bugs, session launcher

- Persist last-set wallpaper and restore it via exec-once, since
  hyprpaper/mpvpaper start every session with nothing loaded
- Fix Vesktop's system tray icon rendering as a broken texture: only
  resolve tray icons through the icon theme when they're actual names,
  not raw pixmap-sourced image:// URLs
- Launch Hyprland via start-hyprland (its official watchdog launcher)
  instead of the raw binary, removing the startup warning and adding
  hang recovery
- Fix Booru panel: Lewds toggle now actually persists, tag autocomplete
  no longer drops/races overlapping requests, and pagination wraps
  instead of overflowing off-screen
- Remove the redundant gap between windows and sidebars/tiles
  (gaps_in/gaps_out, and duplicate flyout margins stacked on top of
  Hyprland's automatic exclusive-zone inset)

modules/scripts/wallpaper-set.sh

@@ -58,3 +58,12 @@ case "${image,,}" in
         hyprctl hyprpaper wallpaper ",$image,$fit_mode" > /dev/null
         ;;
 esac
+
+# Persist so the wallpaper survives a reboot/relogin. hyprpaper/mpvpaper
+# both start every session with nothing loaded — this was previously only
+# ever set at runtime via IPC, so the desktop silently reverted to blank
+# every fresh login. wallpaper-restore (exec-once in hyprland.conf, after
+# hyprpaper starts) re-runs the exact command saved here.
+state_file="$HOME/.config/hypr/wallpaper.conf"
+mkdir -p "$(dirname "$state_file")"
+printf 'wallpaper-set %q %q %q %q %q\n' "$image" "$fit_mode" "$muted" "$speed" "$auto_pause" > "$state_file"