Feature Request: Support multiple Google accounts in Gmail/Calendar MCP integrations

Feature Request

Is your feature request related to a problem?

The built-in Gmail and Google Calendar MCP integrations (mcp__claude_ai_Gmail, mcp__claude_ai_Google_Calendar) currently only support a single Google account. Many users have multiple Google accounts (e.g., personal Gmail + work Google Workspace), each with separate inboxes and calendars.

There is no way to add a second Google account through Claude's settings — the integration only allows one authorized Google account at a time.

Describe the solution you'd like

Support authorizing multiple Google accounts in the Gmail/Calendar MCP integrations, so users can:

• Read emails from both personal and work Gmail accounts
• View and manage calendars across multiple Google accounts
• Distinguish between accounts when calling tools (e.g., via an account parameter or separate tool namespaces like gmail_work_* / gmail_personal_*)

Describe alternatives you've considered

1. Setting up a local open-source MCP server (e.g., mcp-gsuite) for the second account — works but requires creating Google Cloud OAuth credentials, which is a lot of friction for end users.
2. Sharing calendars across accounts — only partially works (read-only, no Gmail access).

Additional context

This is a common use case: personal + work Google accounts. The current single-account limitation means users must choose one or the other, losing access to half their email/calendar workflow.