feat!: PyPI 分发名改为 qca-sdk，与 npm 包名对齐

导入名仍是 qca，元数据查询随分发名改为 version("qca-sdk")。

Author: moonyue-w

README.md

@@ -1,6 +1,6 @@
 # Qoder Cloud Agents Python SDK
 
-[![PyPI version](https://img.shields.io/pypi/v/qca.svg)](https://pypi.org/project/qca/)
+[![PyPI version](https://img.shields.io/pypi/v/qca-sdk.svg)](https://pypi.org/project/qca-sdk/)
 
 The Qoder Cloud Agents Python SDK provides access to the Qoder Cloud Agents API from Python 3.10+. It ships synchronous and natively asynchronous clients, typed request parameters and response models, automatic pagination, SSE streaming, and file transfer.
 
@@ -9,10 +9,10 @@ The API is exposed in two modes, and each has its own client, resources, and typ
 ## Installation
 
 ```bash
-python -m pip install qca
+python -m pip install qca-sdk
 ```
 
-The package is still in pre-release, so the command above resolves to the latest `0.0.1.devN` build. To work from a checkout of this repository instead:
+The distribution is named `qca-sdk`; the import package is `qca`. The package is still in pre-release, so the command above resolves to the latest `0.0.1.devN` build. To work from a checkout of this repository instead:
 
 ```bash
 python -m pip install .

pyproject.toml

@@ -1,5 +1,5 @@
 [project]
-name = "qca"
+name = "qca-sdk"
 version = "0.0.1.dev3"
 description = "Typed synchronous and asynchronous clients for Qoder Cloud Agents"
 authors = [{name = "Qoder"}]

src/qca/_version.py

@@ -1,7 +1,8 @@
 from importlib.metadata import PackageNotFoundError, version
 
 try:
-    __version__ = version("qca")
+    # 分发名是 qca-sdk，导入名是 qca，元数据只认前者。
+    __version__ = version("qca-sdk")
 except PackageNotFoundError:
     # 直接从源码树导入（未安装）时没有包元数据可读。
     __version__ = "0.0.0.dev0"