Update build-metapackage script to include build date and improve copyright information

scripts/build-metapackage

@@ -1,6 +1,7 @@
 #!/bin/sh
 
 set -eu
+umask 022
 
 artifact_dir=${1:-kernel-artifacts}
 output_dir=${2:-dist}
@@ -39,14 +40,29 @@ Upstream-Name: espos-kernel
 Source: https://github.com/esposlinux/espos-kernel-metapackage
 
 Files: *
-Copyright: espOS Project
+Copyright: 2026 espOS Project
 License: GPL-2+
  This package may be redistributed and/or modified under the terms of the GNU
  General Public License version 2 or (at your option) any later version.
 EOF
 
+if [ -n "${SOURCE_DATE_EPOCH:-}" ]; then
+    build_date=$(date -u -R -d "@$SOURCE_DATE_EPOCH")
+else
+    build_date=$(date -R)
+fi
+cat > "$staging_dir/usr/share/doc/espos-kernel/changelog.Debian" <<EOF
+espos-kernel ($METAPACKAGE_VERSION) espos-unstable; urgency=medium
+
+  * Automatically generated metapackage for espOS kernel $KERNEL_VERSION.
+
+ -- espOS Project <danilacasito8@gmail.com>  $build_date
+EOF
+gzip -9n "$staging_dir/usr/share/doc/espos-kernel/changelog.Debian"
+
+find "$staging_dir" -type d -exec chmod 0755 {} +
+find "$staging_dir" -type f -exec chmod 0644 {} +
 chmod 0755 "$staging_dir/DEBIAN"
-chmod 0644 "$staging_dir/DEBIAN/control" "$staging_dir/usr/share/doc/espos-kernel/copyright"
 
 package_file="$output_dir/espos-kernel_${METAPACKAGE_VERSION}_all.deb"
 dpkg-deb --root-owner-group --build "$staging_dir" "$package_file"