chore: update PyPI package name

- update PyPI package name to gradient-chat-client
- update installation line in docs

Author: abswn

README.md

@@ -17,7 +17,7 @@ python3 -m venv venv
 source venv/bin/activate  # Linux/macOS
 venv\Scripts\activate     # Windows
 
-pip install gradient-chat
+pip install gradient-chat-client
 ```
 Or if you want to install the latest development version:
 ```bash

pyproject.toml

@@ -3,7 +3,7 @@ requires = ["setuptools>=61.0", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [project]
-name = "gradient-chat"
+name = "gradient-chat-client"
 version = "0.1.0"
 description = "Unofficial Python client for Gradient Chat (supports gpt-oss-120b and qwen3-235b)"
 authors = [