Agent Teams: teammate spawn fails after brew upgrade due to hardcoded Caskroom version path

Description

When Claude Code is installed via Homebrew (brew install claude-code), Agent Teams appears to resolve and hardcode the absolute Caskroom path at spawn time:

/opt/homebrew/Caskroom/claude-code/<VERSION>/claude

After brew upgrade claude-code, the old version directory is removed, causing teammate spawn to fail because the hardcoded path no longer exists.

Steps to Reproduce

1. Install Claude Code via Homebrew
2. Start a session and create an Agent Teams team (TeamCreate)
3. Spawn a teammate (e.g., Agent with team_name)
4. If brew upgrade claude-code has changed the version since the binary path was resolved, the teammate fails to start

Expected Behavior

Agent Teams should use the stable symlink path (/opt/homebrew/bin/claude) or re-resolve the binary path at spawn time, rather than caching or hardcoding the resolved Caskroom path.

Actual Behavior

Teammate spawn fails (the child process cannot be started because the resolved path points to a removed version directory).

Workaround

Restart Claude Code after brew upgrade.

Environment

• macOS (Apple Silicon)
• Claude Code installed via Homebrew Cask
• Symlink chain: /opt/homebrew/bin/claude → /opt/homebrew/Caskroom/claude-code/<VERSION>/claude