[BUG] Bun crashes with 'incorrect alignment' on Windows ARM64 (v2.1.47 native installer)

Bug Description

Claude Code v2.1.47 native installer crashes on Windows ARM64 (Snapdragon X Elite) with Bun "incorrect alignment" errors. This did not happen on v2.1.45.

Environment

• Claude Code version: 2.1.47
• Installation method: Native installer (claude install)
• OS: Windows 11 ARM64 (build 26200)
• CPU: Snapdragon X Elite (X1E78100) - Qualcomm Oryon
• Shell: MSYS2/Git Bash (MINGW64_NT, x86_64 emulated)
• Node.js: v22.16.0 (win-arm64 native)
• Bun: bundled with native installer

Symptom

Bun runtime crashes with "incorrect alignment" error. The native installer bundles Bun which runs under x86_64 emulation (WoW64) on ARM64 hardware.

Regression

• v2.1.45: Stable, no crashes
• v2.1.47: Crashes occur

Suspected Cause

v2.1.47 release notes include several changes that touch MSYS2/Windows bash handling and memory management:

• "Fixed bash tool output silently discarded on Windows when using MSYS2 or Cygwin shells"
• Multiple memory optimization changes (releasing API stream buffers, trimming agent history, eliminating O(n² accumulation)
• "Fixed Windows terminal rendering bugs caused by os.EOL"

The combination of ARM64 → WoW64 x86 emulation → MSYS2 → Bun creates a fragile stack where alignment-sensitive memory operations can fail.

Workaround

Using npm installation (npm install -g @anthropic-ai/claude-code) with native ARM64 Node.js avoids the Bun runtime entirely and works without crashes.

Notes

• v2.1.47 added "Windows ARM64 (win32-arm64) native binary support" but the Bun runtime bundled may not handle x86 emulation correctly
• The npm-based installation with native ARM64 Node.js works perfectly, suggesting the issue is specific to the bundled Bun runtime