Bash tool stdout is always empty on Windows 11

Environment

• OS: Windows 11 Home 10.0.26200
• Shell: bash (Git for Windows / MSYS2)
• Claude Code backend: DeepSeek API proxy (api.deepseek.com/anthropic)
• Model: deepseek-v4-pro

Symptoms

All bash commands return empty stdout/stderr in tool results, even basic commands like echo hello world. The commands themselves execute successfully (exit code 0, file redirects work correctly).

Steps to Reproduce

1. Run echo hello world via Bash tool
2. Tool result shows "Bash completed with no output"
3. Repeat with any command (pwd, git --version, ls, etc.)

Evidence

• echo test > file.txt → Read tool confirms file contains "test" (commands execute correctly)
• Background tasks show exit code 0 but empty output files
• gh auth status works (confirmed login succeeded) but stdout not shown in tool results
• File redirect + Read workaround works correctly

Workaround

Redirect output to file then read with Read tool:

command > result.txt 2>&1

Then Read result.txt.

Additional Context

The bash shell appears to use Windows-style PATH (semicolons) which bash cannot parse, making basic Unix utilities unavailable (which, ls, uname not found). Full paths to Windows executables do work (e.g., "/c/Program Files/GitHub CLI/gh.exe").