[FEATURE] Google connectors: allow more than one Google account per Claude account

Problem. The Google Workspace connector (Gmail, Calendar, Drive) binds exactly one Google account per Claude user. Connecting a second account replaces the first. Many users have a personal Gmail plus one or more Workspace accounts (for example a personal account, a company role inbox, and a second business domain). Today the only options are to disconnect and reconnect by hand, or route mail through a third-party aggregator connector.

Request. Support multiple Google connections at once, each surfaced as its own MCP server (for example "Gmail (doug@domainA)" and "Gmail (info@domainB)") so tool names and permissions stay scoped per account. Account selection per connection in Settings > Connectors, plus "Add another account."

Why it matters. Role inboxes (info@, support@) are the common case for small businesses. Forcing one account means the connector either reads the wrong mailbox or has to be re-authorized every time the user switches context. Multi-account also removes the incentive to pipe mail through third-party aggregators.

Environment. Claude desktop app (Code tab), macOS 26.5, Claude Code 2.1.x. Reproduces on claude.ai web as well.

Related. No existing issue found for multi-account. Adjacent: #96004 (connector sends from an unseen account), which multi-account labeling would also mitigate.