[Bug] Fullscreen TUI redraw scrolls terminal under GNU screen on WSL2 (regression in 2.1.228)

Bug Description
Title: Fullscreen TUI redraw scrolls host terminal under GNU screen on WSL2 (regression in 2.1.228) --- ## Summary With "tui": "fullscreen", the streaming status area no longer repaints in place when running inside GNU screen. Each redraw scrolls the host terminal natively, so the status block accumulates into scrollback instead of updating a fixed region. Regression between 2.1.227 and 2.1.228. ## Environment - WSL2, Linux 5.15.167.4-microsoft-standard-WSL2 - GNU screen, TERM=screen-256color inside the session - Host terminal: Windows Terminal - Install: native, ~/.local/share/claude/versions/ - Setting: "tui": "fullscreen" in ~/.claude/settings.json ## Reproduction 1. Start GNU screen on WSL2 with altscreen on in ~/.screenrc 2. Launch Claude Code with "tui": "fullscreen" 3. Send any prompt that produces a streaming response Expected: the status area repaints in place. Actual: every redraw scrolls the terminal; the status block is written repeatedly into scrollback rather than updating a fixed region. ## Recovery Switching screen windows away and back (C-a n, C-a p) forces a full repaint and the display is correct until the next streaming response. ## Version bisect - 2.1.226 — clean, no scrolling - 2.1.227 — clean, no scrolling (last known good) - 2.1.228 — reproduces reliably Bisected by launching each binary directly from ~/.local/share/claude/versions/. Currently pinned to 2.1.227 as a workaround. ## Ruled out - termcapinfo xterm* ti@:te@ in ~/.screenrc — removed it, no change; restored it since it wasn't the cause - altscreen on is set - Same screen config worked correctly on 2.1.226 and 2.1.227, so this is not a screen-side configuration change

Environment Info

• Platform: linux
• Terminal: screen
• Version: 2.1.227
• Feedback ID: d7079450-0c67-44eb-b2ec-73eb8d2bad60

Errors

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