Replace separate ACP and agent-types modules with unified AgentManager using provider pattern. Migrate Claude and Codex implementations to provider-specific clients. Streamline session-agent integration, remove old ACP notification types, and introduce agent timeline events. Delete obsolete documentation and test files. Add AgentRegistry for persistence and agent-stream-based communication pattern.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
