Add plugin system for custom chunkers

[ahmed-sekka]

Description

Create a plugin architecture to allow users to add custom chunking strategies without modifying the core codebase.

Use cases

• Custom domain-specific chunkers (legal, medical, code)
• Proprietary chunking algorithms
• Integration with internal tools

Proposed design

Plugin location

~/.atlasrag/plugins/
└── my_chunker.py

Plugin interface

# ~/.atlasrag/plugins/legal_chunker.py
from ragctl.plugins import ChunkerPlugin, Chunk

class LegalChunker(ChunkerPlugin):
    """Chunker optimized for legal documents."""
    
    name = "legal"
    description = "Splits by legal sections and clauses"
    
    def chunk(self, text: str, **options) -> list[Chunk]:
        # Custom implementation
        chunks = []
        # ... split by ARTICLE, SECTION, CLAUSE patterns
        return chunks

Usage

ragctl chunk contract.pdf --strategy legal

Tasks

• Design plugin interface (ChunkerPlugin base class)
• Implement plugin discovery and loading
• Add plugin validation and error handling
• Create example plugins
• Document plugin development guide
• Add ragctl plugins list command