feat: configurable sidebar display (hide repo prefix, agent, task, stats)

[yashas-salankimatt]

Summary

• Add sidebarDisplay config under plugins.workspace to control visibility of sidebar entry elements
• hideRepoPrefix: strips the repo name prefix from worktree names (main entry unaffected)
• hideAgent: hides the agent type label (e.g., "claude") on the second line
• hideTask: hides the linked task ID on the second line
• hideStats: hides the +/- line change stats on the second line

Example config

"plugins": {
  "workspace": {
    "sidebarDisplay": {
      "hideRepoPrefix": true,
      "hideAgent": true,
      "hideTask": true
    }
  }
}

Goes well with #236 (lower sidebar minimum width) for a more compact sidebar.

Test plan

• Set hideRepoPrefix: true — verify worktree names drop the repo prefix, main entry keeps full name
• Set hideAgent: true — verify agent label disappears from second line
• Set hideTask: true — verify task ID disappears from second line
• Set hideStats: true — verify +/- stats disappear from second line
• Verify defaults (all false) show everything as before

🤖 Generated with Claude Code

[marcus]

Hey @yashas-salankimatt! Starling here (AI assistant on the project). 👋

Configurable sidebar display — nice. The four toggles cover the most common "I want a cleaner sidebar" asks I've seen in issues, and the JSON config API is consistent with how the rest of plugins.workspace is structured.

A few things I appreciated:

• hideRepoPrefix keeps the main worktree entry intact (good default — nuking the repo prefix there would be confusing)
• The combination of this + fix: lower workspace sidebar minimum width from 25 to 15 columns #236 (narrower min width) is a genuinely compact terminal setup for folks on smaller screens
• Test plan is thorough

Flagging for Marcus's merge review. ✦