Shell and worktree traps

1. Use absolute paths and your assigned worktree. Never leave a shell inside a worktree about to be removed: cd holds a Windows handle on the folder, and a later git worktree remove fails "Permission denied".
2. Line endings: check the committed blob, git show <rev>:<path>. In Git Bash grep -c $'\r' matches every line, an always-true CRLF test; .gitattributes normalises on commit.
3. Any script with Windows paths, regexes or escapes: write it to a file with your file-write tool and run it by absolute path. A Bash heredoc mangles backslash paths (a worktree path once ended up mangled and was force-removed), collapses \\ to \ in regexes, and can turn \n or \0 into real newline or NUL characters inside a Python file.
4. PowerShell file APIs: [IO.File]::ReadAllText / WriteAllText resolve a relative path against the PROCESS cwd (often the main checkout), not $PWD: a failed read gives $null, then WriteAllText creates an empty stray there. Use your file-edit tool, or an absolute path.
5. python - @'...'@ passes the here-string as an argument, not stdin: Python opens a REPL that can loop and fill the disk. Write the script to a file, or pipe the here-string to Python.
6. A PowerShell function or pipeline returning exactly ONE object gives a bare scalar with no .Count ($null), so $x.Count -gt 0 passes silently: wrap in @() before counting.
7. Subprocesses: pass arguments as an array with the shell disabled.
8. Test output: tee the whole output to a file (or dotnet test --logger trx), then read the file; never grep it live (a case-sensitive filter once matched the pass banner but not the failure text). Never pipe a gate or locked run through a truncating reader.
9. One foreground gate per worktree, on its assigned ports; never background one with a stray & (two at once fought over the same build).
10. Cleanup goes through the kit's tools (python <kit>/tools/worktree_remove.py -C <main checkout> <worktree>), only for a worktree that is yours to remove; otherwise report it to the lander or coordinator.

Never

• git worktree remove --force, git branch -D, deleting another session's branch, or taking over another session's run.
• [IO.File] or [System.IO] with a relative path.
• Kill a process by name.
• Move an assigned worktree to another folder: the configured worktree location holds unless the owner assigns another.

Details: <kit>/docs/worktree-remove.md; <kit>/docs/new-worktree.md.