docs: checking a client is one command now

docs/protocol/index.md

@@ -70,25 +70,39 @@ happens, which is what makes it worth stating.
 `plugrl-protocol` ships a server that grades a client against the
 specification clause by clause and exits non-zero on a violation.
 
-From a fresh checkout of `plugrl-protocol`, two things are not already in place.
-The conformance server imports `websockets`, which is not a declared dependency -
-`pyproject.toml` lists only `numpy` and `msgpack`, so `uv sync` leaves it out. And
-the C++ client is a source file, not a binary, so it has to be compiled first.
-Both steps are what CI does:
+It is one command, and it runs your client for you:
+
+```bash
+uv run --extra conformance plugrl-conformance \
+    --port 8000 --steps 20 \
+    --client "./my_client 127.0.0.1 8000 20"
+```
+
+`--client` is a shell command. The checker starts it **after** the socket is
+listening and waits for it afterwards, so a client that fails to connect fails
+for a reason that is about your client rather than about start-up order. A
+non-zero exit from it is reported as a failure of its own.
+
+Without `--client` the checker waits for a client started elsewhere, which is
+the older two-terminal form and still works.
+
+To check the reference clients in this repository, the C++ one is a source
+file rather than a binary, so it is compiled first:
 
 ```bash
 g++ -std=c++17 -O2 -Wall -Wextra -o /tmp/plugrl_client examples/plugrl_client.cpp
 
-uv run --with websockets examples/conformance_server.py --port 8000 --steps 20 &
-/tmp/plugrl_client 127.0.0.1 8000 20
+uv run --extra conformance plugrl-conformance --port 8000 --steps 20 \
+    --client "/tmp/plugrl_client 127.0.0.1 8000 20"
 ```
 
 `plugrl_client.cpp` uses POSIX sockets (`sys/socket.h`, `arpa/inet.h`), so that
 build needs Linux, macOS or WSL. The Python reference client has no such
 constraint and exercises the same clauses:
 
 ```bash
-uv run --with websockets examples/raw_client.py --host 127.0.0.1 --port 8000 --steps 20
+uv run --extra conformance plugrl-conformance --port 8000 --steps 20 \
+    --client "python examples/raw_client.py --host 127.0.0.1 --port 8000 --steps 20"
 ```
 
 Its report has two severities. A **violation** is something the real server

docs/protocol/index.zh.md

@@ -58,23 +58,36 @@ step state、终止标志 —— 只活在一条连接里。重连的客户端
 
 `plugrl-protocol` 附带一个服务端，它按规范逐条给客户端打分，有违规就以非零码退出。
 
-刚 clone 下来的 `plugrl-protocol` 还差两步。conformance server 会 import
-`websockets`，但它不是声明的依赖 —— `pyproject.toml` 里只有 `numpy` 和 `msgpack`，
-`uv sync` 装不上它；另外 C++ 客户端是源码不是可执行文件，要先编译。CI 做的就是这两步：
+一条命令就够，它会替你把客户端也起起来：
+
+```bash
+uv run --extra conformance plugrl-conformance \
+    --port 8000 --steps 20 \
+    --client "./my_client 127.0.0.1 8000 20"
+```
+
+`--client` 接收一条 shell 命令。检验器会在**端口开始监听之后**再启动它，结束后等它退出——
+这样"客户端连不上"就只可能是客户端自己的问题，而不是启动顺序。客户端以非零码退出
+也会被单独记为一条失败。
+
+不传 `--client` 时，它就等别处启动的客户端连进来，也就是原来那种两个终端的用法，依然可用。
+
+要检验本仓库自带的参考客户端：C++ 那个是源码而非可执行文件，需要先编译。
 
 ```bash
 g++ -std=c++17 -O2 -Wall -Wextra -o /tmp/plugrl_client examples/plugrl_client.cpp
 
-uv run --with websockets examples/conformance_server.py --port 8000 --steps 20 &
-/tmp/plugrl_client 127.0.0.1 8000 20
+uv run --extra conformance plugrl-conformance --port 8000 --steps 20 \
+    --client "/tmp/plugrl_client 127.0.0.1 8000 20"
 ```
 
 `plugrl_client.cpp` 用的是 POSIX socket（`sys/socket.h`、`arpa/inet.h`），
 所以这一步需要 Linux、macOS 或 WSL。Python 参考客户端没有这个限制，
 覆盖的条款是同一批：
 
 ```bash
-uv run --with websockets examples/raw_client.py --host 127.0.0.1 --port 8000 --steps 20
+uv run --extra conformance plugrl-conformance --port 8000 --steps 20 \
+    --client "python examples/raw_client.py --host 127.0.0.1 --port 8000 --steps 20"
 ```
 
 报告分两个等级。**violation** 是真服务端会拒绝或处理错的问题；**note** 是真服务端