Welcome screen not showing on Windows (MSYS2/MINGW64)

Bug Description

The welcome screen (initial TUI splash) does not appear when launching Claude Code on Windows. This happens consistently across directories of all sizes — small folders with just a few files have the same issue, so it's not related to file count or indexing time.

Environment

• Claude Code version: 2.1.41
• OS: Windows 10 (Build 26200) via MSYS2/MINGW64
• Kernel: MINGW64_NT-10.0-26200 3.6.6-1cdd4371.x86_64
• Node.js: v24.13.1
• Terminal: MSYS2 (Git Bash / MINGW64)

Steps to Reproduce

1. Open MSYS2/MINGW64 terminal
2. cd into any directory (tested with large vaults and near-empty folders)
3. Run claude
4. Welcome screen does not appear — goes straight to the input prompt

Expected Behavior

The welcome screen / splash UI should display briefly when launching a new Claude Code session.

Actual Behavior

No welcome screen is shown. The TUI skips directly to the conversation input.

What I've Tried

• Launching from directories with very few files (rules out file count / slow indexing)
• Launching from a fresh temp directory using --add-dir to reference the project
• Updating Claude Code to latest version (2.1.41)
• Migrating from npm to native install via claude install

None of these resolved the issue.

Possibly Related

• #12084 (welcome screen renders then immediately exits on RHEL8)
• This may be a broader TUI rendering issue on non-standard terminals (MSYS2/MINGW64 on Windows)