Implement session/load in goose acp

[cloud-on-prem]

Please explain the motivation behind the feature request. Currently, Goose VS Code extension, and possibly other client implementations cannot load sessions, which means session history will not work.

Describe the solution you'd like Implement session load as per the ACP specifications

Describe alternatives you've considered Unfortunately, there is no alternative as previous protocols/routes are being deprecated in Goose

Additional context This is the spot to turn on the session/load capability. (But possibly requires more work to expose sessions) https://github.com/block/goose/blob/main/crates/goose-cli/src/commands/acp.rs#L573

• [x] I have verified this does not duplicate an existing feature request