feat: Concurrent multi-tool daemon support

[don-petry]

Problem

Current daemon only supports one tool at a time (--tool gemini OR --tool claude). Users must run multiple daemon instances to monitor multiple providers.

Proposed Solution

Support --tools gemini,claude,copilot to run all providers concurrently in a single daemon using asyncio.gather().

• Shared MCP client across providers
• Shared deduplication logic
• Unified dashboard showing all provider activity