Feature request: Allow disabling platform-level MCP integrations (Gmail, Google Calendar, etc.) from CLI settings

Problem

Platform-level MCP integrations (e.g., mcp__claude_ai_Gmail, mcp__claude_ai_Google_Calendar) connected via Claude.ai account are always injected into the Claude Code CLI context. There is no way to disable them from the CLI side.

These tool definitions consume significant context tokens (~16 tools with verbose descriptions), reducing available context for actual coding tasks.

Current behavior

• Plugins have enabledPlugins in settings.json for per-plugin enable/disable control
• Local MCP servers (.mcp.json) can be added/removed per project
• Platform-level MCP integrations have no equivalent disable mechanism
• permissions.deny can block usage but does NOT remove tool definitions from context

Desired behavior

A setting to disable specific platform MCP integrations from Claude Code CLI, similar to enabledPlugins, e.g.:

{
  "enabledMcpServers": {
    "claude_ai_Gmail": false,
    "claude_ai_Google_Calendar": false
  }
}

Or any equivalent mechanism that prevents tool definitions from being loaded into context.

Use case

Users who connect Gmail/Google Calendar on Claude.ai (for web UI use) but don't need them in CLI coding sessions. The context overhead is wasteful for software engineering workflows.