Fleet/agent sidebar view misrenders and mouse clicks misalign above a window-size threshold (Windows Terminal)

Environment

• Claude Code version: 2.1.218
• OS: Windows 11 Home 10.0.26200
• Terminal: Windows Terminal

Bug
Cycling into the agent/fleet sidebar view (left arrow, to view running agents) causes the TUI to misrender once the terminal window is large/maximized: only the right-hand portion of each line renders (content appears clipped on the left), and mouse clicks land on the wrong on-screen element - click targets no longer line up with what is visually displayed.

Repro

1. Open Claude Code in Windows Terminal, maximize the window.
2. With at least one agent running, press left-arrow to cycle into the agent/fleet sidebar view.
3. Observe right-truncated/garbled rendering, and clicking a visible element does not hit it.
4. Shrinking the window down to a smaller size (roughly 1360x790) reliably fixes the rendering; growing it back reproduces the bug.

Ruled out
Initially suspected a Windows Terminal theme regression (had just switched to a Catppuccin color scheme), but the bug is NOT caused by terminal config:

• Reverted experimental.retroTerminalEffect (silently enabled by the Catppuccin theme installer) - no effect.
• Reverted a forced rendering.graphicsAPI: direct3d11 (also silently added by the installer) - no effect.
• Issue persists with both settings back to default, and correlates purely with window size/column count, not font or color scheme.

Suspected cause
Looks like a column-width/layout calculation bug in the fleet/agent sidebar view that only manifests above some terminal width threshold, with the mouse hit-testing grid falling out of sync with the actual rendered layout at that width.