Refactor tools into modular code review and core packages

[suhaibmujahid]

This PR introduces a modular structure for bugbug tools, separating code review, comment resolution, and core utilities into distinct subpackages.

bugbug/tools/
├── __init__.py
├── base.py
│
├── core/
│   ├── data_types.py         # InlineComment, ReviewRequest
│   ├── exceptions.py         # All custom exceptions
│   ├── llms.py               # LLM model integration for all providers
│   └── platforms/
│       ├── base.py           # Abstract Patch, ReviewData
│       ├── phabricator.py    # Phabricator integration (~704 lines)
│       ├── swarm.py          # Swarm integration (~84 lines)
│       └── bugzilla.py       # Bugzilla Bug class (~203 lines)
│
├── code_review/
│   ├── agent.py              # CodeReviewTool (~246 lines)
│   ├── prompts.py            # All prompt templates (~241 lines)
│   ├── langchain_tools.py    # LangGraph tools (~71 lines)
│   └── database.py           # ReviewCommentsDB, SuggestionsFeedbackDB (~175 lines)
│   └── utils.py 
│
└── comment_resolution/
    └── agent.py              # CodeGeneratorTool (~382 lines)

[Copilot]

Pull Request Overview

This PR refactors the bugbug tools codebase into a modular structure, organizing code review and comment resolution tools into distinct subpackages with shared core utilities.

• Introduces a new modular package structure (core/, code_review/, comment_resolution/)
• Separates platform-specific implementations (Phabricator, Swarm, Bugzilla) into dedicated modules
• Maintains backward compatibility through re-exports in __init__.py files

Reviewed Changes

Copilot reviewed 18 out of 21 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
bugbug/tools/core/utils/formatting.py	New module containing diff processing and formatting utilities previously in code_review.py
bugbug/tools/core/platforms/swarm.py	Extracted Swarm platform implementation
bugbug/tools/core/platforms/phabricator.py	Extracted Phabricator platform implementation with duplicate code
bugbug/tools/core/platforms/bugzilla.py	Extracted Bugzilla integration with duplicate code
bugbug/tools/core/platforms/base.py	Base classes for platform implementations
bugbug/tools/core/data_types.py	Core data type definitions
bugbug/tools/core/exceptions.py	Custom exception definitions
bugbug/tools/comment_resolver.py	Updated with deprecation warning
bugbug/tools/comment_resolution/agent.py	Extracted comment resolution agent
bugbug/tools/code_review/prompts.py	Extracted prompt templates
bugbug/tools/code_review/langchain_tools.py	LangGraph tools for code review
bugbug/tools/code_review/database.py	Vector database implementations
bugbug/tools/code_review/agent.py	Main code review agent
bugbug/tools/code_review/init.py	Backward-compatible exports for code review
bugbug/tools/code_review.py	Removed monolithic file (now modular)
bugbug/tools/init.py	Top-level backward-compatible exports

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[marco-c]

langchain_tools.py # LangGraph tools (~71 lines)

We might want to have some in the top directory, shared across because they are useful outside code review, and some under code review.