Remove private implementation hints from marketplace docs

Constraint: Public marketplace documentation must not identify private implementation sources or unpublished capabilities.

Rejected: Explaining omitted MCP servers in public README | the explanation itself exposes private context.

Confidence: high

Scope-risk: narrow

Directive: Public docs should describe only published plugins and generic marketplace rules.

Tested: python scripts/validate_marketplace.py; hidden content and filename scan for private identifiers.

plugins/codex/README.md

@@ -22,6 +22,6 @@ codex plugin marketplace add .
 codex plugin add docx@eapil-skill-market
 ```
 
-每个 `plugins/<plugin-id>` 目录都是一个可安装 Codex plugin。插件可以包含官方支持的 `skills`、`mcpServers`、`apps`、`hooks`、`interface` 和 `assets`。当前公开 MCP 只包含 `mcp-playwright`；KeyInfo 内部 MCP 不发布到公开仓库。
+每个 `plugins/<plugin-id>` 目录都是一个可安装 Codex plugin。插件可以包含官方支持的 `skills`、`mcpServers`、`apps`、`hooks`、`interface` 和 `assets`。当前公开 MCP 插件是 `mcp-playwright`。
 
 完整插件清单、MCP 说明和维护规则见根目录 `README.md`。