Add more extensive typing to openhands/core directory

[neubig]

This PR adds more extensive typing to the openhands/core directory to improve type safety and code quality. The changes include:

1. Adding return type annotations to functions that were missing them
2. Adding parameter type annotations to function parameters
3. Using more specific types instead of generic ones
4. Adding type ignore comments for model_serializer decorators from pydantic
5. Fixed typing in get_llm_config_from_agent to handle None values

These changes will help catch type-related bugs earlier and improve the developer experience with better IDE support.

Note: Only files in the openhands/core directory have been modified. All workflow and config files have been reverted to match the main branch.

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To run this PR locally, use the following command:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:a82764a-nikolaik   --name openhands-app-a82764a   docker.all-hands.dev/all-hands-ai/openhands:a82764a

[neubig]

@OpenHands please check the type: ignore annotations that were added in this PR, and where it is possible to do so without extensive changes, remove these type ignore annotations and fix the underlying problem

[openhands-ai]

I'm on it! @neubig can track my progress at all-hands.dev

[openhands-ai]

I've successfully addressed the request to remove type: ignore annotations in the PR #7728 and fix the underlying typing issues. Here's a summary of the changes made:

Changes Made:

1. Fixed typing in app_config.py:

   • Properly typed the agents dictionary as dict[str, AgentConfig] instead of just dict
   • Removed type: ignore annotations in get_agent_config() method by fixing the return type
   • Fixed get_llm_config_from_agent() method by adding a null check for llm_config_name to handle the case when it's None

2. Fixed typing in message.py:

   • Replaced all # type: ignore annotations on @model_serializer decorators with proper type specifications
   • Added explicit mode='plain' parameter to all @model_serializer decorators to properly type the serializer functions

Verification:

• Ran mypy type checking through the pre-commit hooks, which passed successfully for our changes
• The pre-commit hooks did fail for other unrelated issues (ruff linting and formatting), but those were outside the scope of our task

Commit and Push:

• Committed the changes with message "Remove type: ignore annotations and fix underlying typing issues"
• Successfully pushed the changes to the fix/core-typing-improvements branch

All the type: ignore annotations that were identified in the PR comment have been successfully removed, and the underlying typing issues have been fixed without requiring extensive changes to the codebase.

[csmith49]

I think if we remove the agent_name = ... line (and update references downstream to name) we can set the type of name directly to name: str = 'agent'.

[csmith49]

I don't believe there's any inter-op issues between the typing imports like Dict or just using the class itself as an annotation (like dict), but the majority of the existing annotations use the latter style. Do we want to standardize on one or the other?

[csmith49]

A couple of notes but otherwise LGTM

[neubig]

@OpenHands please reflect csmith49's review comments, and also merge main and fix any merge conflicts

[openhands-ai]

I'm on it! @neubig can track my progress at all-hands.dev

[openhands-ai]

I've successfully addressed the PR comment by reflecting csmith49's review comments and merging main into the branch. Here's a summary of the changes made:

Changes Made:

1. Addressed csmith49's review comments:

   • Fixed the get_llm_config_from_agent method in app_config.py by removing the unnecessary agent_name variable and simplifying the parameter type to just str instead of str | None
   • Standardized typing annotations in message.py by replacing imported types like Dict and List with built-in types like dict and list throughout the file

2. Merged main into the branch and resolved conflicts:

   • Fixed merge conflicts in openhands/core/cli.py by adopting the newer implementation from main that uses prompt_toolkit instead of the older implementation
   • Added proper return type annotations to maintain type safety

3. Fixed a type error in session.py:

   • Modified the _create_llm method to handle the None case before calling get_llm_config_from_agent, ensuring type compatibility

4. Verified changes with pre-commit hooks:

   • Ran the pre-commit hooks to ensure our changes passed mypy type checking
   • Fixed all type errors related to our changes

All the requested changes have been successfully implemented and pushed to the fix/core-typing-improvements branch, updating PR #7728. The PR now reflects csmith49's review comments and has been merged with the latest changes from main.