Support per-project OAuth sessions for MCP plugins (e.g. Figma)

Feature Request

Problem

Currently, MCP plugins that use OAuth authentication (like Figma) store a single global OAuth session. This means it's impossible to use different accounts in different projects.

Use Case

As a developer working on multiple projects for different organizations, I need to connect to different Figma accounts (different teams/orgs) depending on the project I'm working in. For example:

• Project A uses Figma account user@company-a.com
• Project B uses Figma account user@company-b.com

Currently, I have to manually log out and log back in every time I switch projects, which breaks the workflow.

Proposed Solution

Allow OAuth sessions for MCP plugins to be scoped per project, similar to how mcpServers in .mcp.json or ~/.claude.json are already scoped per project path. This could be implemented as:

1. Storing OAuth tokens per project path (e.g., keyed by project directory in ~/.claude.json)
2. Or allowing an optional account or profile field in the plugin config that maps to different stored sessions

Affected Plugins

Any HTTP MCP plugin using OAuth, including:

• Figma (figma@claude-plugins-official)
• Potentially Atlassian, Slack, and other OAuth-based MCP servers

Current Workaround

Manual logout/login via /mcp → select plugin → re-authenticate. This is not practical for frequent project switching.