refactor(bot): Extract platform-agnostic tool system

[RSO]

Summary

This PR introduces a tool registry system that enables dynamic tool loading based on the owner's integrations, laying the groundwork for:

• Supporting multiple chat platforms (Discord, Teams) beyond Slack
• Adding new tool integrations (GitLab, Sentry, Axiom) without modifying core bot logic

Changes

New Tool System (/src/lib/bot/tools/)

• types.ts: Core type definitions (BotTool, ToolResult, ToolExecutionContext, RequesterInfo)
• registry.ts: Global tool registry with registerTool, getTool, getAllTools
• tool-loader.ts: Dynamic tool loading based on owner's active integrations
• implementations/spawn-cloud-agent.ts: Extracted spawn_cloud_agent tool
• index.ts: Barrel export with auto-registration

Updated slack-bot.ts

• Removed ~180 lines of hardcoded tool code
• Now uses getToolDefinitionsForOwner() to dynamically load tools
• Uses getTool() from registry to execute tool calls
• Tools only available if owner has the required integration (e.g., github)

Architecture

Tool Registry (startup)
    └── spawn_cloud_agent (requiredIntegration: 'github')
    └── [future tools...]

Request Flow:
    1. getToolDefinitionsForOwner(owner)
       └── Check owner's integrations
       └── Filter tools by requiredIntegration
    2. LLM calls tool
    3. getTool(name).execute(args, context)

Testing

• Manual testing of Slack bot with spawn_cloud_agent tool
• Verified tool is only available when owner has GitHub integration

PR Stack

This is PR 1 of 7 in the Slack bot tech debt reduction initiative:

1. Tool System (this PR)
2. Bot Core extraction
3. Platform Adapter interface
4. Slack Adapter implementation
5. Simplified Webhook routes
6. Context Provider system
7. Generic logging with migration