Use standard lower-case deb

pkg/deb/debian/postinst

@@ -0,0 +1,42 @@
+#!/bin/sh
+# --------------------------------------------------------------
+# SPDX-License-Identifier: GPL-3.0-or-later
+# --------------------------------------------------------------
+# deb File      : postinst
+# File Authors  : sanchuanhehe <wyihe5520@gmail.com>
+# Contributors  :   Nil Null   <nil@null.org>
+#	            |
+# Created On    : <2025-06-14>
+# Last Modified : <2025-06-16>
+#
+# postinst script for chsrc
+# --------------------------------------------------------------
+
+set -e
+
+case "$1" in
+    configure)
+        # Update man database
+        if command -v mandb >/dev/null 2>&1; then
+            mandb -q /usr/share/man/man1/chsrc.1 2>/dev/null || true
+        fi
+
+        # Make sure chsrc is executable
+        chmod +x /usr/bin/chsrc
+
+        echo "chsrc has been successfully installed!"
+        echo "Run 'chsrc help' to get started."
+        ;;
+
+    abort-upgrade|abort-remove|abort-deconfigure)
+        ;;
+
+    *)
+        echo "postinst called with unknown argument \`$1'" >&2
+        exit 1
+        ;;
+esac
+
+#DEBHELPER#
+
+exit 0