Bug: Translucent sidebar flickers abnormally when switching

Description
The translucent (半透明) sidebar frequently exhibits abnormal flickering/glitching when toggling or switching between views.

Steps to reproduce

1. Open Codex Desktop
2. Toggle the translucent sidebar open/closed, or switch between sidebar sections
3. Observe visual flickering — brief flashes, ghost frames, or inconsistent opacity transitions

Expected behavior
Smooth, consistent sidebar transition without flicker artifacts.

Actual behavior
During sidebar toggle/switch, the translucent layer flickers — intermittent bright/dark flashes or partial redraws visible.

Environment

• Codex Desktop (latest stable)
• macOS (Apple Silicon)

Additional context
This appears related to the translucent/blur rendering pipeline during state transitions. Possibly a compositor race or missing intermediate frame during opacity animation.