docs: claude code doesn't know user-level MCP config locations

Problem

When asked to inspect or migrate user-level MCP settings, Claude Code did not immediately know the canonical storage locations and instead explored many unrelated files before finding the answer.

Expected behavior

Claude Code should know (and document clearly) that user-level MCP server configurations are stored in:

1. ~/.claude/settings.json → mcpServers key (added via claude mcp add --scope user)
2. ~/.mcp.json — global shared MCP config (newer format)

Actual behavior

Claude Code went through a lengthy, unfocused exploration:

• Read settings.json looking for mcpServers (correct but no result)
• Ran claude mcp list (returned nothing)
• Browsed ~/.claude/ directory listing
• Checked settings.local.json, plugin caches, ToolHive configs
• Eventually found ~/.mcp.json by accident via find

Suggestion

• Add a concise knowledge entry or inline comment in the codebase/docs that explicitly states the two canonical locations for user-level MCP config
• Ensure claude mcp list output (or --help) references these file paths so users and the model can locate them immediately