Document how to use the OKF4net MCP server with VS Code

[jchable]

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

Context: OKF4net.Mcp (okf-mcp) is a standard stdio MCP server, but src/OKF4net.Mcp/README.md only documents Claude Desktop/Code. VS Code has first-class MCP support (agent mode / GitHub Copilot), so a short recipe lets any VS Code user consult an OKF bundle from the editor.

Files to touch: src/OKF4net.Mcp/README.md (add a ### Use with VS Code section); optionally cross-link from the root README.md "Use OKF in Claude (MCP)" section.

What to do:

1. Add a ### Use with VS Code section to src/OKF4net.Mcp/README.md.
2. Show a workspace .vscode/mcp.json (VS Code uses a "servers" object, each entry with "type": "stdio", "command": "okf-mcp", and the bundle path in "args"), plus the user-level mcp.json alternative. Reference the current VS Code MCP docs: https://code.visualstudio.com/docs/copilot/chat/mcp-servers
3. Mention enabling the server in agent mode and the OKF_MCP_READONLY=1 option.

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.