fix: avoid pipefail error in appimage build script

The `set -euo pipefail` combined with `| head -50` causes the script
to fail when head closes the pipe early and sed receives SIGPIPE.
Wrap the pipeline in a subshell with `|| true` to ignore the expected
pipe error.

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

Author: sinelaw

crates/fresh-editor/scripts/build-appimage.sh

@@ -154,7 +154,8 @@ chmod +x "$APPDIR/AppRun"
 
 echo ""
 echo "=== AppDir structure ==="
-find "$APPDIR" \( -type f -o -type l \) | sed "s|$APPDIR|Fresh.AppDir|" | head -50
+# Use subshell to avoid pipefail issues with head truncating output
+(find "$APPDIR" \( -type f -o -type l \) | sed "s|$APPDIR|Fresh.AppDir|" | head -50) || true
 
 echo ""
 echo "=== Building AppImage ==="