fix(hooks): unset git env vars in pre-commit vendor check for worktree support

When running from a git worktree, git exports GIT_DIR, GIT_WORK_TREE, and
GIT_INDEX_FILE into the hook environment. These variables caused git commands
inside vendor sub-repos to use the parent project's metadata instead of the
vendor's own .git directory, producing thousands of spurious "deleted" entries
and blocking commits.

The fix unsets these three variables before the vendor-scanning loop. By that
point PROJECT_ROOT and COMPOSER_COMMITS are already captured, so the unset
is safe. Each vendor sub-repo then discovers its own .git directory naturally.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: LTSCommerce

CLAUDE/Plan/worktree-git-env-fix.md

@@ -0,0 +1,62 @@
+# Plan: Fix pre-commit hook for git worktree support
+
+## Problem
+
+The `pre-commit-check-vendor-uncommitted` hook fails in git worktrees. When a
+commit is made from a worktree, git exports `GIT_DIR` (and potentially
+`GIT_WORK_TREE`, `GIT_INDEX_FILE`) into the hook's environment. These variables
+point to the worktree's git metadata, not to vendor sub-repos.
+
+When the hook `cd`s into a vendor directory and runs `git status --porcelain`,
+git ignores the vendor's own `.git` directory and instead uses the inherited
+`GIT_DIR`. This causes git to compare the vendor directory against the
+*parent project's* index, producing thousands of spurious "deleted" entries
+and blocking the commit.
+
+### Reproduction
+
+```bash
+# From a worktree:
+export GIT_DIR="/workspace/.git/worktrees/worktree-child-00024-contact-sections"
+cd /workspace/vendor/lts/php-qa-ci
+git status --porcelain | wc -l
+# => 2984 (all wrong — the vendor repo is actually clean)
+
+# After unsetting:
+unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
+git status --porcelain | wc -l
+# => 0 (correct)
+```
+
+## Fix
+
+In `git-hooks/pre-commit-check-vendor-uncommitted`, unset `GIT_DIR`,
+`GIT_WORK_TREE`, and `GIT_INDEX_FILE` before entering the vendor-scanning loop.
+These variables are only meaningful for the *parent* repository's commit
+operation; vendor sub-repos must discover their own `.git` directory naturally.
+
+The `PROJECT_ROOT` is captured from `git rev-parse --show-toplevel` *before*
+the unset, so it correctly resolves even in worktree context. The `composer.lock`
+parsing also happens before the unset and doesn't use git at all.
+
+### Variables to unset
+
+| Variable         | Why it breaks vendor checks                            |
+| ---------------- | ------------------------------------------------------ |
+| `GIT_DIR`        | Forces git to use parent's git dir instead of vendor's |
+| `GIT_WORK_TREE`  | Overrides the working tree, misaligning status checks  |
+| `GIT_INDEX_FILE` | Points to parent's index, not vendor's                 |
+
+### Placement
+
+Unset immediately before the `while` loop that iterates vendor `.git`
+directories (line 77). This is after `PROJECT_ROOT` and `COMPOSER_COMMITS`
+are already captured, so those values are unaffected.
+
+## Success criteria
+
+1. Hook passes in a normal (non-worktree) repo with clean vendors
+2. Hook passes in a worktree context with clean vendors
+3. Hook still correctly detects real uncommitted changes in vendor repos
+4. Hook still correctly detects composer.lock out-of-sync conditions
+5. `PROJECT_ROOT` resolution is unaffected (captured before unset)

git-hooks/pre-commit-check-vendor-uncommitted

@@ -73,6 +73,16 @@ if [[ -f "$PROJECT_ROOT/composer.lock" ]]; then
     ' "$PROJECT_ROOT/composer.lock" 2>/dev/null)
 fi
 
+# Unset git environment variables before scanning vendor sub-repos.
+# When this hook runs from a git worktree, git exports GIT_DIR,
+# GIT_WORK_TREE, and GIT_INDEX_FILE pointing to the worktree's metadata.
+# If these leak into vendor sub-repo git commands, git ignores the vendor's
+# own .git directory and reports thousands of spurious changes against the
+# parent project's index. Unsetting them lets each vendor repo discover its
+# own .git naturally.  PROJECT_ROOT and COMPOSER_COMMITS are already captured
+# above, so this is safe.
+unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
+
 # Find all vendor/*/* directories that contain .git directories
 while IFS= read -r -d '' git_dir; do
     # Get the repo directory (parent of .git)