Add support for MCP progress reports and MCP tasks

[aidansommers]

What would you like to be added?

For long running operations, it would be very helpful for Gemini CLI to support sending a progressToken in the request metadata to appropriate MCP servers.

Why is this needed?

See the documentation below regarding this standard.
https://modelcontextprotocol.io/specification/2025-11-25/basic/utilities/progress
https://modelcontextprotocol.io/specification/2025-11-25/basic/utilities/tasks
https://gofastmcp.com/servers/progress
https://gofastmcp.com/servers/tasks

As MCP Servers become more mature, many are building out with such capability in mind and rely on these for user experience. If not supporting these, other MCP Clients that do will fair better with the surrounding ecosystem.

I believe this would also help with the ongoing efforts regarding A2A operations (and similar efforts).

Additional context

No response

[gemini-cli]

Hi @aidansommers, thank you for your interest in helping triage issues!

The status/need-triage label is reserved for project maintainers to apply. This helps us ensure that an issue is ready and properly vetted for community contribution.

A maintainer will review this issue soon. Please see our CONTRIBUTING.md for more details on our labeling process.

[jasmeetsb]

/assign