chore: bump version to 2.0.19

update changelog to 2.0.19

Author: mhduiy

debian/changelog

@@ -1,3 +1,9 @@
+dde-shell (2.0.19) unstable; urgency=medium
+
+  * feat: enhance notification animations and visual effects
+
+ -- zhangkun <[email protected]>  Fri, 14 Nov 2025 10:30:15 +0800
+
 dde-shell (2.0.18) unstable; urgency=medium
 
   * fix: fix collapsed tray item visual index