fix: set MCPORTER_CONFIG env for all mcporter subprocess calls

[jygzyc]

Summary

• Add get_mcporter_env() static method to base Channel class to set MCPORTER_CONFIG environment variable
• Update all mcporter subprocess calls to use this environment for consistent config path resolution
• Update documentation to include export MCPORTER_CONFIG=~/.mcporter/mcporter.json instruction

Changes

• base.py: Add get_mcporter_env() method
• bosszhipin.py, douyin.py, exa_search.py, linkedin.py, xiaohongshu.py: Pass env=self.get_mcporter_env() to subprocess calls
• setup-exa.md, setup-xiaohongshu.md, install.md: Add MCPORTER_CONFIG export instruction

This ensures all mcporter commands use the correct config file location.

[Panniantong]

感谢 PR！想确认一下这个修改解决的具体场景是什么？

mcporter 默认会读取 ~/.mcporter/mcporter.json，正常安装流程（agent-reach install）不需要手动设置 MCPORTER_CONFIG 环境变量。

如果是特定环境下 mcporter 找不到配置文件的问题，能否补充一下复现步骤？这样我们可以判断是在 Agent Reach 层面修还是在 mcporter 层面修。

另外有个顾虑：硬编码 ~/.mcporter/mcporter.json 会影响配置文件不在默认路径的用户（比如 OpenClaw 用户的 mcporter 配置在 workspace 目录下），可能导致 doctor 误报。

[jygzyc]

感谢 PR！想确认一下这个修改解决的具体场景是什么？

mcporter 默认会读取 ~/.mcporter/mcporter.json，正常安装流程（agent-reach install）不需要手动设置 MCPORTER_CONFIG 环境变量。

如果是特定环境下 mcporter 找不到配置文件的问题，能否补充一下复现步骤？这样我们可以判断是在 Agent Reach 层面修还是在 mcporter 层面修。

另外有个顾虑：硬编码 ~/.mcporter/mcporter.json 会影响配置文件不在默认路径的用户（比如 OpenClaw 用户的 mcporter 配置在 workspace 目录下），可能导致 doctor 误报。

我这边经过正常安装流程之后，默认会在 $HOME 目录下新建一个 config 目录，所以我增加设置环境变量的部分

[Panniantong]

Hi @jygzyc 👋 Thanks for the PR!

Before we proceed, could you share what specific issue you ran into? Was mcporter unable to find its config file in certain environments?

A few thoughts on the current approach:

1. agent-reach install already configures mcporter — during installation, mcporter config add writes to the default config path. So in most cases, mcporter should find its config without needing MCPORTER_CONFIG explicitly set.

2. Adding env= to every subprocess call is quite invasive (9 files changed). If there's a specific scenario where mcporter can't find its config, we might be able to fix it more simply — e.g., ensuring the install step writes to the right default path, or setting the env var once at install time in the user's shell profile.

3. Adding export MCPORTER_CONFIG=... to user-facing docs adds a manual step that ideally shouldn't be needed.

Could you describe the scenario where this breaks? For example:

• Running as a different user than who installed?
• Using a non-standard HOME?
• Running inside a container?

Happy to work together on a targeted fix once we understand the root cause 🙂