Add MCP (Model Context Protocol) support

[davesleal]

Description

Integrate with Model Context Protocol to enable using Claude Code subscription instead of API, and connect to other MCP servers.

Background

MCP allows Claude to access external resources and tools through a standardized protocol.

Proposed Features

1. MCP Server Mode: Run SlackClaw as an MCP server

   • Expose Slack channels as resources
   • Allow Claude Code to read/write to Slack

2. MCP Client Mode: Connect to other MCP servers

   • GitHub MCP server for repo access
   • Filesystem MCP for code navigation
   • Custom MCP servers for tools

3. Hybrid Architecture

   • Use Claude Code locally via MCP
   • Leverage user's existing subscription
   • Zero API costs for conversations

Implementation

• Implement MCP protocol handlers
• Create Slack resource provider
• Connect to Claude Code via MCP
• Document MCP configuration

Benefits

• Use existing Claude subscription
• Access to MCP ecosystem
• Extensible architecture
• Zero API costs

References

• https://modelcontextprotocol.io/
• https://github.com/anthropics/anthropic-quickstarts/tree/main/model-context-protocol