A skills cleanup also removed the MCP and editor configs, and four docs still point at them

[melbinjp]

13a8e28a ("refactor: remove all old unused skills", 2026-03-04, on main) removed the old
skills trees. It also removed five files that are not skills:

.agent/mcp_config.json
.codex/config.toml
.cursor/mcp.json
.opencode/mcp.json
.vscode/extensions.json

Of those directories only .claude/ is still on main. .agent/, .codex/, .cursor/,
.opencode/ and .vscode/ are gone entirely.

Four places still tell a contributor to use them:

• docs/contributing-lint-setup.md:77 : "The repository includes .vscode/extensions.json
  and .vscode/settings.json. On first open, VS Code will prompt you to install the
  recommended Ruff extension."
• docs/contributing-lint-setup.md:103 : "Codex CLI (OpenAI, v0.101.0+) is supported via
  .codex/config.toml (MCP server config). This file is tracked in git."
• docs/environment-setup.md:106 : "Restart Cursor to load the MCP servers from
  .cursor/mcp.json"
• docs/developer-guide.md:81 and :138, in the project-structure tree: .codex/ as
  "Codex CLI project config" and .agent/ as "Antigravity IDE: mcp_config.json + skills
  (symlinks)"

One of those is wrong for a second reason. .vscode/settings.json has no add-or-delete
history at all:

$ git log --oneline --diff-filter=AD -- .vscode/settings.json
$

It was never tracked, so that sentence did not become false in March. It was never true.

No patch, because the two fixes are opposite diffs and only you know which one you want.
Either the MCP and editor configs come back, or the docs stop promising them. The Codex line
is the one I would fix first whichever way you go, since it states the file is tracked in git
as a fact a reader can act on.

Found with docproof, which checks what documentation
claims against what the repository actually contains.