Add `claude mcp restart` command

Feature request

Add a claude mcp restart <name> command to restart a running MCP server process.

Motivation

When developing an MCP server locally, the typical workflow is: edit source → rebuild → need the running server to pick up changes. Currently the only way to restart is:

claude mcp get my-server          # copy the full config
claude mcp remove my-server -s user
claude mcp add ... my-server ...  # re-add with all env vars, args, etc.

This is error-prone (env vars with special characters, easy to miss flags) and tedious for a common development workflow.

Proposed solution

claude mcp restart <name>
claude mcp restart          # restart all

This would kill the running server process and re-launch it with the same configuration.

Alternatives considered

• A file watcher that auto-restarts on dist/ changes — heavier, not always desired
• Documenting the remove/re-add workaround — works but shouldn't be necessary