fix: Windows hook execution for Claude Code 2.1.x

[obra]

Summary

• Fix Windows hook execution for Claude Code 2.1.x
• Add .gitattributes to enforce LF line endings for shell scripts
• Deprecate polyglot wrapper with explanatory comment

Root Cause

Claude Code 2.1.x changed the Windows execution model for hooks. It now auto-detects .sh files in hook commands and prepends bash on Windows. This broke the polyglot wrapper because:

"run-hook.cmd" session-start.sh

became:

bash "run-hook.cmd" session-start.sh

...and bash cannot execute a .cmd file.

Changes

• hooks/hooks.json: Call session-start.sh directly instead of using the polyglot wrapper
• hooks/run-hook.cmd: Add deprecation comment explaining Claude Code 2.1.x change (kept for reference)
• .gitattributes: Enforce LF line endings for shell scripts and common text files
• RELEASE-NOTES.md: Add bug fix entry

Test plan

• Verified bash "C:\Users\...\hooks/session-start.sh" works with mixed path separators
• Test on Windows with Git Bash
• Test on Windows with WSL
• Test on macOS/Linux (no regression)

Closes

• Fixes Windows: SessionStart hook fails due to CRLF line endings and polyglot script issues #317 (Windows: SessionStart hook fails due to CRLF line endings and polyglot script issues)
• Fixes [Bug] SessionStart:startup hook error #275 ([Bug] SessionStart:startup hook error)
• Fixes [Windows] Blank terminal window opens on Claude Code startup due to -l flag in run-hook.cmd #292 ([Windows] Blank terminal window opens on Claude Code startup)
• Supersedes fix: handle WSL bash as default shell on Windows #282 (fix: handle WSL bash as default shell on Windows)

🤖 Generated with Claude Code

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