Summary

Add wt.delete-hook config and --delete-hook CLI flag to run custom commands before worktree deletion, mirroring the existing wt.hook creation hook pattern.

What Changed

• internal/git/config.go: Added configKeyDeleteHook constant, DeleteHooks field to Config, and loading logic in LoadConfig()
• cmd/root.go: Added --delete-hook flag, flag override in loadConfig(), wired hook execution into deleteWorktrees() before worktree removal, updated help text
• e2e/config_test.go: Added TestE2E_DeleteHooks with 8 subtests and updated completion flag list

Design Decisions

• Hooks run before worktree removal so the directory still exists and commands can execute inside it (e.g., git push origin --delete $(git branch --show-current))
• If a hook fails, the deletion is aborted and the worktree is preserved
• Hooks do not run when deleting a branch without an associated worktree (no directory to execute in)
• --delete-hook flag overrides wt.delete-hook config, consistent with --hook / wt.hook
• Reuses the existing git.RunHooks() function — no changes needed to internal/git/hook.go

Usage

# Persistent via git config
git config --add wt.delete-hook "git push origin --delete $(git branch --show-current)"

# One-off via flag
git wt -D --delete-hook "echo cleaning up" my-branch

Test Plan

• go build ./... compiles cleanly
• go test ./... — all existing tests pass
• 8 new e2e subtests pass: flag, config, multiple hooks, branch-only skip, flag-overrides-config, failure-prevents-deletion, working directory verification, stderr output