Cleaner agent switching ux in the TUI

[krissetto]

Give it a try and let me know if this is worth a cleanup pass

⚠️ Ignore the code for now, plenty of vibes and it has not been thoroughly looked into.

• Makes the sidebar agents section its own component (as an example for future refactoring of all sections)
• Cleans up agent view in the sidebar to only show essential agent info (name and model)
• Allows switching by clicking on the agent in the sidebar
• Adds proper agent selection dialog with more info per agent and easier to read descriptions, including expandable toolset/tool list

Screencast

Screencast.From.2026-02-01.21-54-38.mp4

[krissetto]

/review

[github-actions]

Code Review Summary

Found 1 high-severity issue in the new toolset unwrapping logic that could cause a nil pointer panic.

Issues Found

• HIGH: Nil pointer dereference risk in getToolsetDisplayName function

What Looks Good

• Context cancellation properly handled in background goroutine
• Mutex protection correctly implemented for cache access
• Click handling and bounds checking are solid
• Agent picker dialog implementation looks safe

[github-actions]

Nil pointer dereference risk in toolset unwrapping

The unwrap loop assigns ts.Unwrap() directly to toolset without checking if the result is nil:

for range 5 {
    if ts, ok := toolset.(interface{ Unwrap() tools.ToolSet }); ok {
        toolset = ts.Unwrap()  // ← Could be nil
        continue
    }
    break
}

If any of the Unwrap() implementations (like filterTools.Unwrap(), replaceInstruction.Unwrap(), or toonTools.Unwrap()) return nil (which can happen if the wrapper was constructed with a nil ToolSet field), this will assign nil to toolset. While the subsequent type assertion won't panic directly, continuing with a nil toolset could cause issues.

Recommendation:
Add a nil check after unwrapping:

for range 5 {
    if ts, ok := toolset.(interface{ Unwrap() tools.ToolSet }); ok {
        if unwrapped := ts.Unwrap(); unwrapped != nil {
            toolset = unwrapped
            continue
        }
        break
    }
    break
}