Enable the developer agent behind a feature flag

[begelundmuller]

Usage instructions:

Enable the feature flag:

# rill.yaml
...
features:
  developer_agent: true

Connect using the CLI chat (rill start must be running in another terminal):

rill chat --local

Example prompt:

> Can you add a model with mock Shopify data for me?
...

Limitations:

• It can only create models and metrics views
• It can only update existing models

How to update the agent:

1. Update the prompts in runtime/ai/developer_agent.go or runtime/ai/develop_model.go
2. Add an eval in runtime/ai/developer_agent_test.go
3. Run the eval with this command, then check the transcripts in runtime/ai/evals:

RILL_RUNTIME_TEST_MODE=expensive go test -run ^TEST_NAME$ github.com/rilldata/rill/runtime/ai

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!

[nishantmonu51]

👍