chore(main): release 0.3.15 (#555)

🤖 I have created a release *beep* *boop*
---


##
[0.3.15](v0.3.14...v0.3.15)
(2025-11-19)


### Features

* Add client-side extension support

([https://github.com/a2aproject/a2a-python/pull/525](https://github.com/a2aproject/a2a-python/pull/525))

([https://github.com/a2aproject/a2a-python/commit/9a92bd238e7560b195165ac5f78742981760525e](https://github.com/a2aproject/a2a-python/commit/9a92bd238e7560b195165ac5f78742981760525e))
* **rest, jsonrpc:** Add client-side extension support

([https://github.com/a2aproject/a2a-python/commit/9a92bd238e7560b195165ac5f78742981760525e](https://github.com/a2aproject/a2a-python/commit/9a92bd238e7560b195165ac5f78742981760525e))

---
This PR was generated with [Release
Please](https://github.com/googleapis/release-please). See
[documentation](https://github.com/googleapis/release-please#release-please).

---------

Co-authored-by: Lukasz Kawka <luk.kawka@gmail.com>

Author: a2a-bot

CHANGELOG.md

@@ -1,4 +1,12 @@
-# Changelog
+ # Changelog
+
+## [0.3.15](https://github.com/a2aproject/a2a-python/compare/v0.3.14...v0.3.15) (2025-11-19)
+
+
+### Features
+
+* Add client-side extension support ([#525](https://github.com/a2aproject/a2a-python/issues/525)) ([9a92bd2](https://github.com/a2aproject/a2a-python/commit/9a92bd238e7560b195165ac5f78742981760525e))
+* **rest, jsonrpc:** Add client-side extension support ([9a92bd2](https://github.com/a2aproject/a2a-python/commit/9a92bd238e7560b195165ac5f78742981760525e))
 
 ## [0.3.14](https://github.com/a2aproject/a2a-python/compare/v0.3.13...v0.3.14) (2025-11-17)