Feature Request: Add logging configuration for custom agents

Feature Request

Add a logging or debug field to the agent frontmatter configuration for custom agents defined in .claude/agents/*.md files.

Use Case

When developing and debugging custom agents, it would be helpful to enable verbose logging to see:

• Tool calls made by the agent
• Agent reasoning/decision points
• Input/output of agent invocations
• Timing information for performance analysis

Proposed Solution

Add a logging configuration option to the agent frontmatter:

---
name: my-agent
description: ...
model: opus
logging: true  # or a more granular config
---

Or with more granular control:

---
name: my-agent
description: ...
model: opus
logging:
  enabled: true
  level: verbose  # or: minimal, normal, verbose
  output: ~/.claude/debug/agents/  # optional custom path
---

Current Workaround

Running claude --debug provides some visibility, but it's all-or-nothing and not agent-specific.

Benefits

• Easier debugging during agent development
• Ability to enable logging for specific agents without affecting others
• Better observability for complex multi-agent workflows