[Bug] Thinking effort descriptions are truncated in the model picker hover card

[xinyi-gong]

Environment

• OS: Windows
• Eclipse Version: 2026.3
• Plugin Version: 0.18.0

Describe the bug
In the model picker hover card, the description text for each Thinking Effort
level is cut off and not fully visible.

To Reproduce
Steps to reproduce the behavior:

1. Open the Copilot Chat view.
2. Click the model picker and hover over a reasoning-capable model
   (e.g. Claude Sonnet 4.6).
3. Observe the Thinking Effort section in the hover card.

Expected behavior
Each effort level's description is fully readable

Screenshots

Additional context
Add any other context about the problem here.