feat: adds cursor-agent as a cli provider

[roshbhatia]

This PR adds Cursor's new CLI as an additional CLI provider akin to the current Claude Code/Gemini CLI providers.

You can use a config file akin to this for local testing:

GOOSE_PROVIDER: cursor-agent
GOOSE_MODEL: gpt-5 # the model currently available for the free tier, which I used for testing

CURSOR_AGENT_COMMAND: cursor-agent

Which results in output akin to this (ran in a dirtied branch):

starting session | provider: cursor-agent model: gpt-5
    logging to /Users/rshnbhatia/.local/share/goose/sessions/20250814_125236.jsonl
    working directory: /Users/rshnbhatia/github/personal/roshbhatia/goose

Goose is running! Enter your instructions, or try asking what goose can do.

Context: ○○○○○○○○○○ 0% (0/128000 tokens)
( O)> What have we changed in this branch, compared to the main branch? List files only.
Running a quick diff against the merge-base with `main` to list all files changed on this branch (including uncommitted and untracked files).### Changed files vs main (including untracked)

- crates/goose-cli/src/scenario_tests/provider_configs.rs
- crates/goose/src/providers/base.rs
- crates/goose/src/providers/cursor_agent.rs
- crates/goose/src/providers/factory.rs
- crates/goose/src/providers/githubcopilot.rs
- crates/goose/src/providers/mod.rs
- documentation/docs/getting-started/providers.md
- documentation/docs/guides/cli-providers.md

note:

• Clippy linting seems to be complaining about complexity, although I yoinked the corresponding functions from the Claude Code/Gemini CLI providers -- not sure what's flagging the complexity rule here, any guidance? I avoided changing the implementation for the problematic function given that it seemingly passes fine for the other cli providers.
• My apologies for the previously two opened + closed PRs, my upstream branch was out of sync and I kept bungling the history cleanup.

[jamadeo]

Thanks @roshbhatia ! If clippy complains about complexity make sure to merge main -- we've dropped that lint rule. Just also make sure to cargo fmt.

[roshbhatia]

@jamadeo done!

[michaelneale]

@roshbhatia nice - did you get past the clippy constraint?

What I think we shoudl do as part of this, given this is growing, is in the docs/text make it clear that cli providers won't have the same capabilities as direct providers, and have limited support (especially on different platforms like windows), as once we merge, people (rightly) expect things to just work, but there is often a bit of extra config needed, may not work on windows (eg claude and others have limited support there, lost a few days to find that out) - WDYT?

I like this!

[michaelneale]

added a proposed change above

[michaelneale]

I think this is ok - I will do a follow up with note of supportability of cli providers

[angiejones]

couple of doc improvements requested 🙏🏽

[michaelneale]

thanks @angiejones have addressed - and used a warning markdown indicator I hope looks ok

has been addressed

[angiejones]

one of my comments wasn't implemented properly. will open a new PR

[roshbhatia]

@roshbhatia nice - did you get past the clippy constraint?

What I think we shoudl do as part of this, given this is growing, is in the docs/text make it clear that cli providers won't have the same capabilities as direct providers, and have limited support (especially on different platforms like windows), as once we merge, people (rightly) expect things to just work, but there is often a bit of extra config needed, may not work on windows (eg claude and others have limited support there, lost a few days to find that out) - WDYT?

I like this!

Seems like this was merged, but yes -- did get past the clippy constraint by merging main back in.