[Windows][multi-monitor] Codex window border spills onto adjacent display

Summary

On a dual-monitor Windows setup, when Codex Desktop is maximized or docked on the primary display next to the monitor boundary, a narrow part of the Codex window remains visible on the adjacent display.

The overflow looks like a vertical white/gray strip, approximately 10–15 pixels wide including the border/shadow. It is subtle over a light or colored background and very obvious over a black background.

Environment

• Codex Windows package: 26.727.6591.0 (x64)
• Windows 11 Pro, build 26200
• Two displays, both 2560x1440
• Primary display bounds: 0,0 2560x1440
• Left secondary display bounds: -2560,0 2560x1440
• Windows taskbar is at the top; working areas are 2560x1400

Steps to reproduce

1. Use two side-by-side displays, with the secondary display positioned to the left of the primary display.
2. Open Codex Desktop on the primary display.
3. Maximize or dock the Codex window against the left boundary of the primary display.
4. Look at the right edge of the left secondary display.
5. Observe a narrow vertical strip from the Codex window extending onto the secondary display.

Expected behavior

The maximized/docked Codex window, including its border and shadow, should remain fully inside the selected monitor's working area.

Actual behavior

A narrow white/gray border or shadow is rendered on the adjacent monitor. Against a black background it appears as a persistent bright vertical line.

Two redacted screenshots were captured on the adjacent display using green and black backgrounds. They contain no project, conversation, account, or repository content and will be attached separately.