update CHANGES.md

Author: clarasb

chartlets.js/CHANGES.md

@@ -6,6 +6,11 @@
 	- `vite: ^8.0.16`
 	- `vitest: ^4.1.8`
 
+* Added `visible` support for progress components. Progress indicators can
+  now be hidden via `visible={false}` and are automatically shown while a
+  server-side callback with an output such as `Output("progress", "visible")`
+  is pending.
+  
 ## Version 0.2.0 (from 2026/03/11)
 
 * Updated dependencies

chartlets.py/CHANGES.md

@@ -1,5 +1,9 @@
 ## Version 0.2.1 (in development)
 
+* Added `visible` property to the base `Component` class, so components can
+  be shown or hidden through callback outputs such as
+  `Output("progress", "visible")`.
+  
 ## Version 0.2.0 (from 2026/03/11)
 
 * Added `size` and removed `variant` property from `IconButton`