Fix issue #2647: Planning LLM authentication with custom providers

[devin-ai-integration]

Description

This PR fixes issue #2647 where authentication fails when using OpenAI-compatible LLMs with planning=True but without specifying a planning_llm.

The fix makes the CrewPlanner inherit authentication parameters (base_url, api_key, etc.) from the agent's LLM when planning_llm is not specified. This enables seamless use of planning with custom LLM providers.

Changes

• Modified CrewPlanner to accept an agent_llm parameter
• Updated Crew._handle_crew_planning to pass the first agent's LLM to CrewPlanner
• Made CrewPlanner inherit authentication parameters from agent_llm when planning_llm is not specified
• Added tests to verify the fix works

Testing

• Added tests that verify planning LLM inherits authentication parameters
• Ran existing tests to ensure backward compatibility

Link to Devin run: https://app.devin.ai/sessions/bb14b018f8cb480a95b9f663cca46aff

Requested by: Joe Moura (joao@crewai.com)

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring