Document how to use the OKF4net MCP server with Visual Studio 2022

[jchable]

Difficulty / est. effort: ~1h, small (docs + config)

Context: Visual Studio 2022 is the primary .NET IDE and gained MCP support for the Copilot agent. Since okf-mcp is a standard stdio MCP server (src/OKF4net.Mcp/README.md currently documents only Claude), a recipe lets VS users browse/validate an OKF bundle from the assistant.

Files to touch: src/OKF4net.Mcp/README.md (add a ### Use with Visual Studio 2022 section).

What to do:

1. Add a ### Use with Visual Studio 2022 section.
2. Show the VS MCP config (a .mcp.json in the solution directory and/or %USERPROFILE%\.mcp.json) with command: "okf-mcp" + bundle-path args. Verify and link the current VS Copilot MCP documentation for the exact schema and minimum VS version.
3. Mention agent-mode usage and OKF_MCP_READONLY=1.

How to verify:

1. dotnet tool install -g OKF4net.Mcp (installs okf-mcp).
2. Point the config at a small test bundle (e.g. tests/fixtures/ has example bundles, or make a throwaway one with a single type:-tagged concept).
3. Restart the editor, open its MCP/agent panel, and confirm the okf server connects and the OKF tools appear (okf_read_concept, okf_browse, okf_graph, okf_search, okf_validate_bundle, okf_changes_since).
4. Ask the assistant to read or browse a concept from the bundle and confirm it works. Add a OKF_MCP_READONLY=1 note for read-only use.

Docs-only change — no build impact — but run dotnet build OKF4net.sln to be safe.

Good to know: Model the new section on the existing "Use with Claude Desktop" block in src/OKF4net.Mcp/README.md (same command: "okf-mcp" + bundle-path args, or OKF_BUNDLE_ROOT env). MCP is a standard stdio protocol, so the server itself needs no change — only the client-side config differs. See CONTRIBUTING.md. If you get stuck on a config format, open a Discussion.