PR Critic Functionality

[turian]

PR Checklist Critic Functionality

What problem or use case are you trying to solve?

When reviewing PRs, it's difficult to track what items from original requirements remain unaddressed. OpenHands users currently must manually verify checklist completion, which is time-consuming and error-prone.

Describe the UX of the solution you'd like

A "PR Critic" functionality that:

1. Concatenates ("cats") the following information into a single context:

   • The repository instructions (and possibly a dedicated PR critic configuration file)
   • The entire linked issue discussion
   • The entire PR discussion thread

2. Uses this concatenated context with a user-defined prompt:

   Based on the repository instructions, linked issue, and PR discussion, list the 
   MOST to LEAST important things remaining to be fixed in this PR.
   Focus on unaddressed requirements, incomplete checklist items, and any discrepancies
   between requested and implemented changes.
   

3. Outputs a prioritized list based on this prompt:

   ## MOST to LEAST important things remaining to be fixed in this PR
   
   1. [HIGH] Description of critical issue #1
   2. [HIGH] Description of critical issue #2
   3. [MEDIUM] Description of somewhat important issue
   4. [LOW] Description of minor issue
   

Do you have thoughts on the technical implementation?

• The prompt should be customizable in a config file
• The system should simply concatenate the inputs and pass them to the LLM with the prompt
• No complex analysis logic needed - just rely on the LLM with sufficient context
• Could be triggered via a slash command like #pr-critic

Describe alternatives you've considered

• More complex analysis systems - Unnecessary when LLMs can handle this with proper prompting
• Manual review processes (current approach) - Time-consuming
• Fixed templates - Not adaptable to different project needs

Additional context

This approach leverages the LLM's capabilities directly rather than building complex analysis systems. By concatenating all relevant information and using a clear prompt, we can get a useful prioritized list of remaining tasks with minimal development effort.

Related #7261

@malhotra5 @neubig