fix(python-sdk): bump pyproject.toml version to 0.9.0

pyproject.toml was left at 0.8.0 when Cargo.toml was bumped to 0.9.0,
causing maturin to build and upload 0.8.0 wheels instead of 0.9.0.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ZhiXiao-Lin

sdk/python/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "a3s-code"
-version = "0.8.0"
+version = "0.9.0"
 description = "A3S Code - Native Python bindings for the AI coding agent"
 readme = "README.md"
 license = {text = "MIT"}